Good things - This build for Jungling Warwick I believe is a great build. Warwick is a well rounded champion who is easy to play, as well jungle with. He can solo Dragon at a very early level, a very good ganker with the use of Flash and his Ultimate, Ifinite Duress, and red buff, making his attacks slow his target.
Bad things - While jungling, there will be a solo lane with a 1 v 2. That person must be highly skilled to maximize EXP while taking little to no damage. Your teammate have to forget last hitting, and focus on staying alive, even if it has to come down to tower hugging. Advice to a solo laner would be to get Teleport in case of a gank or Blitzcrank pull or whatever it may be. Teleporting back makes thing quick and easy with minimal damage to your turret.

These Masteries help maximize damage within the jungle early game and late game, and keep the monster buffs (Blue, Red, Baron) 15% longer. Extra armor penetration and attack speed helps. You always want to use Smite as much as possible after your first go around in jungling. Through your masteries, Smite has a reduced cooldown, and if it kills a minion, it will grant you extra gold. These offensive masteries maximize damage to minions and armor penetration to have a quicker kill in the jungle. It allows you to move faster to get to ganking quicker.

Many Warwick guides choose his W (Hunters Call) first for jungling. I disagree, getting Q (Hungering Strike) first allows you to get a burst of HP quickly with one strike. Also, after you kill the Ancient Golem for blue buff at the start of the game, it is impossible to run out of mana, so you can constantly use Hungering Strike. His abilities are very easy to use. When running low on health, use Q. In a fight, always use W for increased attack speed. E is a passive, so no need to worry about even clicking it. Use R to your team's benefit. It stuns whoever it is casted upon. Use it on the opposing team's carry, or whoever is dealing the most damage. It can lock them down while your teammates deal a bunch of damage.

Smite is obviously a needed tool for Jungling, again, always use when up for it will give you extra gold. WAIT AND USE SMITE AT THE APPROPIATE TIME! While fighting Ancient Golem for blue buff at level 1, use Smite to ensure the kill, so no enemy team can steal in the beginning of the game. Flash is always a very useful summoner spell, whether it is being used to have a quick get away over a wall or creating space, or closing the gap on a gank to ensure a good use of his ultimate, Infinite Duress. Use your spells wisely.

Alrighty, my route for jungling is very simple. YOU ALWAYS START AT BLUE BUFF! , some people start at wraiths and I just don't get it. You may ask for a leash on blue buff to take less damage and get the job done quicker. Then you move over to Wolves. Once you down them, you move across middle lane and kill the wraiths. Then you move on to red buff, by now you should have the correct abilities to stay alive without cutting your HP close. Remember to always use a health potion when needed. After red buff, there should be a lane to gank, but if not, move over to golems, then there should definitely be a ganking opportunity. They may have wards down, but not common in regular games. You want to make sure you ensure at least one kill if it is in the 2 person lane. It may take using Flash and then your ultimate to stun him. Make sure you always target the carry or weakest champion.

Always be looking to gank early in a game, many players do not use wards early game. If your teammates lane is being pushed back to their turret, that is the best time to gank opposing player(s). If your solo lane were to die for any reason, you can help by staying in the lane while your teammate recovers. Warwick is a balanced champion, and a very good 1 v 1 champion. Using that to your advantage will help greatly. Using Q and with all his attack speed and lifesteal, he is nearly impossible to kill 1v1.

Starting off with Cloth Armor and Health Potionx5 makes the best choice for jungling at early levels. Using your health pots when needed, like at level 1 when you fight Ancient Golem for Blue Buff first. Madred's Razors makes jungling easy because you have a nice chance for hitting rougly around 520 damage to a minion. You want to get boots and then rush Madred's Bloodrazors. Madred's Bloodrazors is the best item for Warwick period. It helps his ultimate do a lot more damage, and gives him attack speed. Black Cleaver applies on hit effects then stack on the opponent while using his ultimate. Bloodthirster gives him even more lifesteal, HP, and damage. Frozen Mallet applies slowing effects on your target, closing the gap. Sunfire Cape makes him do small amounts of AoE damage and makes him beefier with more HP.

Well guys, this was my build and rundown of Jungling Warwick. I hope you guys check it out and use it your advantage if you like it. Have fun jungling and dominate!