this build is pretty much a volibear laning guide, I prefer laning then jungling even if its a viable option with volibear but that's personal preference because of its speed. hopefully it will help or inspire some people. do note that you are partially a tank so some items and or item priority will vary depending of the enemy you will face.

Let us make this short, you killer move is frenzy This should be the skill you get first to try and get first blood at lvl 1 if you hide in the bush with your laning partner, plus the passive attack speed it gives is always good. its the first skill you should max and remember to use it as a finishing blow since its cool down should in most case not allow you to use it more then once per fight early game.

now as you can i see In my guide i like to have all 3 basic skills by lvl 3 but thats simply because I like variety and to have what I consider more options. ( I find it also helps me harass abit faster but that again is up for debate)

you should max the skills in this order if you wish to follow this guide:
1- frenzy
2- rolling thunder
3- majestic roar
and of course level up your ult whenever you can.

Your core items are in this build warmog armor and atma's impaler more health will empower your frenzy and the impaler will give you decent armor aswell as giving you a decent attack boost to your basic attack. which are increased in speed with your frenzy.

if you look up you'll see the items i took for this build are:
- warmog armor
- mercury's treads
- atma's impaler
- trinity force ( overall good item and because of the speed bonus it gives to your run / walk speed and attack speed i prefer it to what most people recommend being frozen mallet )
- wit's end
- last item varies, for this i took guardian angel but depending what you are facing, being more of an ad team glacial heart anr raduin's omen of even thorn mail can do the trick and for a more ap team force of nature or banshee's veil can do the trick.
If you feel you have more of a support role and you still lack speed even with trinity you can go for an early shurelya's reverie for its passive. of if you feel like you are dominating you could even for for a madred's bloodraiser

I go for ghost walk and heal.
heal is fantastic with the bear's passive ability, and ghost is an overall good skill with him since its good for escape or to initiate.
there are some alternative such as cleanse and exhaust but the previously mentioned are more to my liking, but this build is just there to help you make your own so feel free to change it or adapt it to your own liking

Volibear is a melee champ and even with his charge, facing ranged champions can be a pain since most of them have some crowd control move or a way to escape you because you reach them or simply keep poking you before you can attack them effectively. thats why when you lane your best laning partners are ranged carry or someone with a ranged cc effect.

your worst nightmare i find when in lane however are probably caitlyn and teemo.
a good caitling will use her traps or her net to hinder your charge and teemo's poison and blind will keep poking you or make your physucal attack useless with its blind.