Abathur is a very strange Hero and one of the hardest to play with. It shouldn't be your first character. If you want to be a good Aba (and you want!), you should know basics of playing other heroes. You have to know that playing Aba without good team would be very frustrating, he can't do much alone. But with good players, you will be a real pain in the enemy ***es.

This guide contains a build, which will be quite easy to use, without resigning from Aba's power. I marked some talents as "not recommend", not because they are bad, I just think first steps with Aba should be different :) I'll try to put comments about what I think about particular talents. Enjoy!

Strong
+ gaining XP from safe distance
+ can help actually everywhere
+ Mines give a vision
+ backdoor
+ Z

Weak
- till 10, your team fights 4v5
- very weak himself, easy prey for Zera and Nova
- hard to play
- you have to be very map aware

Symbiote - elementar ability. With it you can appear everywhere - on a minion, hero, structure (all allied). It also opens the door to next abilities such as Stab , Spike Burst and Carapace. 4 second cooldown, allows you to change lanes very quickly.

Toxic Nest - first of all, they give you a vision. At highest levels you can use them, to quick "Z" to some bush, and spawn locust near enemy structures. Secondly - when you get Vile Nest they will really piss off enemy players. Imagine a retreating guy who goes through your mine field. Damage + slow? How wonderful!

Locust Strain - yay, we like it! Extra minion is a good minion and if it's a minion with more health, dealing more damage, just like locust do, we like it even more. After getting ranged attack locust will do a big destruction. However, locust spawns just from you, so Zeratul or Nova, can use it as GPS and find out your location.

Symbiote Abbilities

Stab - Basic, because of 3 second cd. You will use it quite often - to attack minions but also to help allied heroes in fights. It will be helpful in many situation - you can use it while your ally will try to escape or in just opposite situation. Anyway, extra damage is always nice option.

Spike Burst - Nice in teamfights but because of 6 second cd you won't use it often against heroes. The best way to use it is killing minions. Many liitle guys will receive damage from burst. That's what we like.

Carapace - Sometimes you just need some extra HP which is a matter of life and death. It can save your team mate from death but also it will be helpful while laning. Some extra HP to minions is an advantage, especially while no enemy heroes are nearby.

Abathur is a very interesting character - you can really build him in many directions. My build is quite universal, it will be helpful for new Aba players. It's also a good balance if you cannot decide between mines and locust. I also tried to come up a build, you don't need to be a pro to use.

Red - do not recommend
Yellow - yeah, sometimes ok
Green - good option
underline - my advise

Level 1

- Pressurized Glands - Not bad, but it wouldn't be my choise. It's deffinietly a good option if you have Illidan in the team, but if you don't, choose something else. Spike Burst has quite a long cooldown, and even with decreasing it to 5 seconds, it won't be you most common use abbility.

- Survival Instincts - IMHO it's the best option. Locust is a powerful tool, escpecially in later game. 40% duration is a huge difference, also extra 50% health makes our locusta very big ants. It will also great work with Locust Brood on later levels. Safe and nice option. Do it!

- Regenerative Microbes - shield lasts for 8 second, so easy maths ( 8 * 31) gives us something like 248 heal. However, the shield could be easily destroyed, so this talent won't be such useful as it seems to be. You can consider this talent if you don't have proper healer in the team, but if you decide on this, you should definietly go Sustained Carapace on next level.

Envenomed Nest - maybe, but it's not the best option on this level. If you want to try full mine build, you can try it. Also, it could be useful if enemy team is full or low HP heroes ( The Lost Vikings, Valla, Jaina). It also works nice with Prolific Dispersal.

On first level there are no bad options, but I think that locust is the best one to do some nice push. And gainign XP is the deffinietly what Aba should do before 10 level.

Level 4

Prolific Dispersal - this option is ok, especially if you have taken Envenomed Nest. If enemies have Zeratul, Nova, or if they just roam a lot, it will piss them off.

Ballistospores - Also quite nice, especially on big maps. There is no point taking it on Dragon Shire, Towers of Doom or Battlefield Of Eternity but Crused Hollow is perfect map for this talent. Mines everywhere and increased duration? Sounds good, doesn't it?

Sustained Carapace - Another talent that works good on Cursed Hollow. Sometimes it could be good, but it should be a combo with Carapce talents on 1 and 7 levels. When you don't have enough heal, it's an option you should think about.

Adrenal Overload - This is very good talent, adn will help your team in every fight - no matter if it's 1v1 or 4v5. I would go this talent, if you don't play Aba very good. Another safe and good option.
Tip: Works great with Falstad

Level 7

- Needlespine - another help in fights. Extra damage is very nice thing, but I'm not convinced if you really need range. Hmm, not bad option but i think there is a better choice on this level

- Vile Nest - This will really piss off your enemies. Four 4 second of slowing is very often enough to get a nice kill on a furgitive. If you'll put your mines wisely, it will be really a reat option.

- Networked Carapace - it's not bad talent, especially if you have taken any of Carapace talents before. Helpful both for hero fights and pushing.
Tip: If pushing, use it on Locust. Otherwise it won't be given a shield.

- Calldown:MULE - it's a nice talent, if you don't have a support, or if enemies do really hard push. MULE will let you to repear your structures. It's very helpful talent for Towers of Doom and Sky Temple

Level 10

Ultimate Evolution - that's what we were waiting for! You can clone every allied hero, no matter how far you are, and appear near to him. Finally, your team can win teamfights.
Tip: Try to use Ultimate Evolution on heroes, who can put a lot of damage in short time ( Kael'thas, Jaina, Li-Ming), or heroes with good CC ( Diablo, Anub'arak, Uther).
Ultimate Evolution on Falstad will let you to fly above the furgitives, slow them, and kill one by one.
On Zagara you'll get extra push line! More than this - if you put mine, somewhere, Zaga can set there a Nydus Network. You can use it to destroy enemy forts, without any warning ;)
Big Tip- NEVER USE Ultimate Evolution ON HEROES YOU"VE NEVER PLAYED. Just clone these you know how to play.

- Evolve Monstrosity - actually nice talent, but Ultimate Evolution is just better. If you team can fight enemies without extra hero, you can go Monstrosity. You can control her, but if you'll leave the big zerg alone, it will know what to do with enemy forts.

Although Monstrosity is easier to use, I would go Evolution. Otherwise, teamfights will be hard for your team.

Level 13

Assault Strain - it's very good talent! So you'll probably ask why yellow colour? Easy answer - Bombard Strain] is just better.

Bombard Strain - both locust options are very good here, however i like this one more. It will help you to do a massive push, especially if you are going to take Locust Brood (and you are going to!)

Spatial Efficiency - I'm not a fan of that. Stab has very low cooldown, collecting charges is not needed to it.

Soma Transferance - Same thin as with Pressurized Glands - if you have Illidan take it. Also if you have chosen a Pressurized Glands it seems to be a must have

Level 16

Envenomed Spikes - this one is very nice, and if you have taken any of Spike Burst talents before it's must have. If you have more specialists in the team, it deffinietly should be your chioce. If not, better take Locust Brood. However Envenomed Spikes will never be a bad option.

Adrenaline Boost - nice talent, can someone save some friend ***es, and if you have taken Carapace talents before, you should deffnietly consider this.
Tip: Imagine Thrall using Windfury to chase with extra move speed from you. Tasty?

Locust Brood - That;s what we've been waiting for. 3 locusts at once + this you create passively! Just amazing! If you camp at some bushes near fort, you can easilly destroy enemy structures. This talent give you a lot of power!
Tip: Now you can solo do merc camps. Just wait for you passive locust, adn then spawn Brood. Symbiote and do the rest! :D

Volatile Mutation - useless. Ultimate Evolution cd is just too long, to maximium the usage of it. Better go some other talent.

Level 20

Evolutionary Link - may look good, but it isn't. This shield rarely safes anyone, cos mostly you'll clone ranged assassins, who should be back, not taking damage. However, if you'll clone Diablo or other tank, it may not be the worst option on earth.

Evolution Complete - nope, At level 20 most lanes will be cleaned out, so Tunnel for Monstorinity won't be such useful, as it seems to be.

Hivemind - it's very good talent if you have team that can work as a team, and no yolo guys solo attacking three enemies! However, it's hard to use, and this guide is for begginers so it's not recommended by me. Try it, if you will that you can play Aba.

Locust Nest - ultra annoying talent to play against it. Additional locust is good locust, and you can put it in strategic place. Yes, it will deffineitly be a good option!
Tip: Always mine the Nest place. Assassins with half life, who will try to get easy kill on you, will die just for Nest ^^

Hope this guide will help you love Abathur. It's one of my favorite characters and there are so many options of building him that I'll never get tired of it. I wish I helped you, guys! See you in the Nexus!
PS: If something is not really correct in English, I am very sorry, I don't use it language as good as I wished to. Leave me a comment to edit something, which you cannot understand :)