I found i've started to love voli once i found out a good build. can't help you much with jungle route, i just kinda go through and gank, but for items, I might be able to help you out
Start with a machete, 5 health pots, and majestic roar. go for blue first and clear out the rest of the jungle. Maxing your skills should be in priority of: Frenzy, Majestic Roar, Rolling Thunder.
For items, I LOVE getting a static shiv first thing, it goes well with his character, adds good damage, and works with his build. For his boots, get either, Mercury Treads, Ninja Tabi, or Boots of Swiftness (for easier throws.) After you have boots and shiv, go for a Warmog's, adds good damage to frenzy and defense. after Warmog's, go for a Spirit Visage, it increases your health regen, and with warmog's and your passive, you will get about 200+ health regen. totally not op. For the last two items, I get an Atma's and another situation item, but they can always be substituted.
I love that build because you become so tanky, and you get great AoE damage with shiv and your ult. I managed to tank and tear at a team's health with this build. I just love it.
Hope this helped at all!