Hey summoners! I use this build almost every game and my average score with him is about 8 kills 1 death and close to 10-15 assists depending on my teammates. I've had him since day 1 and I can honestly say I don't see many people playing him because most people dont know what to get. He's a very vital asset to a team in 3v3 and is just as good and maybe even better in 5v5 games due to his abilities and laning/farming abilities. He can easily dish out close to 500+ dmg from crits and can easily score finishing blows because of his E and Q combo. This guide should be sufficient enough to get any new or veteran player get out and own some noobcakes (or skilled players) with this hardcore build that is both fun and rewarding.

Pros
1)Staying in lane is a breeze mid and late game and scoring aces help your team to victory
2) He can slow very well around 15 minutes of gameplay (If you are somewhat fed/get a minimum of 4 kills or 3-5 assists and at least one kill) and pick up ganks fast in late game.
3) E and Q abilities are amazingly powerful in team battles and solo fights (if they have low health)
4) He is a good chaser and can easily take down/hunt foes and snipe/assassinate them one by one till he turns into the ape from return of the planet of the apes! =P
5) He is a monkey! =)
Cons
1) Not the best solo'r based on my experiences BUT that doesn't mean he isn't good.
2) His ult is more of a knock up than an actual guaranteed kill giver. (NOT a bad thing though)
3) He isn't very good against mages that deal high AoE (Karthus, Vladmir's Ult, Swain, Veigar, Ryze, etc.)

This is based on effectiveness and how well it is at the level designated:
1) Level up his E or jump/dash attack first so that u can harass and XP block enemies early. This will give a nice advantage to you and reward your team with better ganking chances.
2) His Q should be used only when attacking enemies and to not be wasted on minions (except baron/dragon/red buff/blue buff)
3) Use his E and then his Q if you aren't harassing and are going for damage/a kill.
4) A nice way to jump in and get out is using your E then Q then W. BUT if you dont have enough health just go for a E then W out and run.
5) Use his W not only to run but to also re-position inside blind spots and move further into their base/territory. Using his W can be used to perfection and create a cat and mouse scenario where you transform from the mouse into a ferocious tiger (still a cat) and chomp up some weaksauce noob-burritos.