I've made many builds but this is my first slightly in depth, close to complete guide.

Simple guide of the Jungle:
1. First off, buy a cloth armor and two health potions. Begin your jungle route at the two small golems, then to the wraiths, and then to the wolf camps using your two health potions and any abilities when needed.
2. Recall. Buy a Long Sword. Redo the jungle route in part 1.
3. Recall again. Buy Madred's Razors. Go straight to the golem blue buff, get the buff, and then redo the jungle route in part one using a health potion when needed.
4. Recall once again. Buy Boots of Speed. Go straight to the lizard red buff, get the buff and attempt your first gank. Keep in mind that you should always try to gank with the red buff and also, by the time you're finished this jungle route, steps 1 through 4 you should be level 6 and ready to cast your ultimate.

Marks - Desolation

Seals - Dodge
- Resilience

Glyphs - Warding
- Alacrity

Quint. - Desolation
- Fortitude

I recommend following this entire item build besides either Wit's end or Malady. If you need the extra magic resist I'd go with Wit's End. They both give you great attack speed.

Also, I'd recommend getting a Frozen Mallet for the extra health and attack damage if you seem to be dying more than hoped, or feel too squishy.

Smite - This is the source of Warwick's successful ganking and his thrive in the jungle.

Flash - A great spell to work with ganks and escaping tough situations.

Ghosts - A great spell as well but I personally think the Blood Scent ability makes up for it.

Teleport - Good for teleporting to wards in the jungle and preforming unexpected ganks.

Cleanse - Great spell for chasing and escaping.

Exhaust - Great spell for ensuring s successful gank, kill, or escape.