Hello this is my first build. I love volibear, he is one of best junglers for team and he has great ganks, he is pretty tanky, and he can deal some nice damage as well.

+ One of best tanks for team
+ One of best passives
+ Strong ganks
+ Easy jungle clearing

- Hard in early game
- You have to be damn good in early game if you don't want to suck in late game
- Easy to counter (vayne..)

First pick definitly Warmog. It will give you advantage with combination of your passive (it will regenerate more hp) and your W will deal more dmg. You need Mercury's early for Teranicity. Spirit visage has usefull passive (combinate with voli's passive..). TF for offensive play, Sunfure cape is good defensive pick for later game. You are going to buy Randuin on almost any tank, awesome stats on this item. I don't buy Banshee very often but some players love that item so if you want, buy it. Just be carefull about having too much magic resist and not enough armor.
Wit's end is specific item, just same warning as item before.

Start with blue, than go for big wraith really fast. If you are suspicious about enemy stealing your red use your pots and hurry to red. Than kill it fast and clear golems. Rest is up to you.

In late game, be ready and when some enemy come close use Q and kill him immidietly. You don't have to worry about hp, your passive will safe you almost always in late game. You can get kills easily with high burst dmg on W. You have to consider if you want to steal it to your carry. Ulti is strong for teamfights and have low CD, use it in EVERY teamfight.