as runes, make sure you don't have any more than 13 arm pen, more is worthless for junglers now, you'r better off with arm yellow, magic res blue, hp quints, and red arm pen. You'r looking to get about 100hp from the runes, some armor 5+, 10 magic res, 10-11 arm pen MAX. As masteries, blue tree seems to become very nice for the huge +hp buff, assists on goldz and lowered minion damage as well as 6 return, which diminishes wraiths. Red tree not very viable since again we'r not going high on ad items and focusing rather on tankiness. But don't worry this are just runes and talents, they will let you stay in fights the longest, and i saw myself doing most dmg in games many times over now. And since the jungle nerf you really kill stuff very fast so i blue tree is no brainer now really. (as red i throw in 3 hp runes and yellow 3-5 hp runes as well)
start cloth armor 5 pots. Blue>wolfs>wraiths>golems>red
look up the lanes, can you gank top or mid, pushed and below 60% 70% hp? gank. not pushed, ask your support for cv on enemy jungle see if you can catch them off guard.
first back buy red crystal, and kindle if you got enough gold, after that you'r looking to get mercury threads, warmong that's your core build warmong gives huge buff to your w.
skilling order prio r>w>e>q with 1 point in q at lvl 3 or 4 to gank depending on your preference.
If enemy team is heavy on ap build kindle into visage, if not build it into shure later, don't forget to activate it in tfs and chasing when you do get it. Good items to have in your build also, trinity force, randiun's, DO NOT get atma it's **** for you your abilities depend on hp and ap, not on AD, forget about buying ad or arm pen items. Mallet is also very nice. Usual tanking items FoN or thornmail depending who's getting fed in enemy team, guardian angel as end item is nice as well. Key points for items is no ad items, lots of hp items, tankish items and aura like shu or even aegis if you'r rich, if not rich tell your support to get it. I'm going to try out tiamat's synergy with ult later on see how that goes, but i'm pretty sure not worth bothering since i won't have much ad or atck speed. God i wish they ever make this item viable on anyone but twitch.
In team fights, don't rush to waste your q, it's best used chasing people that means don't dump it at the start unless you are sure you can catch someone off guard and bounce them to your friendlies. Ultimate at the start of piles, w every cd do NOT keep it to ks, that's gay. e at the start as well.
But all in all i'm mad about the new jungling i hate the exp and gold debuff it's just such a pain. I know riot wanted more active games and all they want junglers to gank more. But what if your lanes are jsut pushed or there's no way you can gank successfully, than you really are screwed because you slowly WILL be falling back on exp and gold which will snowball like a *****. I have not yet tried pedobear at top lane, but i'm fairly confident high sustains like garen nasus ire will just cut you off farm and outfarm you rather easily. To me volibear's only calling is the nerfed jungling, it's a shame because if he came before this jungle nerf he really would have become one of the best junglers, but for now the best ones are those who have aoe spells for faster clearing, like mao, shu, rammus and amumu. Champions like sin and ww who are more single target based really got a bummer this time. Especially the sin's classic lvl 2 blue golem gank at 2nd minute, that was my favourite ;(