Your jungle route as Vi is very straightforward, which allows room for you to change it based on your early game goals/plans. I always start golems, which allows me to take red with 1 pot. I skip raptors and go straight to wolves, then blue. If I was given a good gank, that allows me to gank a lane before recalling to buy.

I get a lot of **** for my build. Most people, pros included, build Vi as more of a tank. It works, but it's not her full potential.
Vi is a secondary assasin, and that is how I play her. Building offensive options is the best way to bring her to max potential. That's all I need to say, look mat the items.

Combo for takedowns: Q in, 1 AA, E, 2 more AA, E, if they are getting away at any point in here, use R. You can also use R to initiate.