So heres a small setup I use for Udyr, to the point in the last few games ive had the enemy team add me to try and find out what rank my main account is, and why im playing a "smurf"(?) account, which I gather is some sort of new account so I can get matched up with noobs, or something to that effect.

I am however, a fresh lvl 30, unranked and only just finished my rune sets, but I have had outstanding performances with Udyr so far. Including a near Hexakill (Got the pentakill, tanked 2 turrets at the enemy spawn while I chased thresh 3 times around their core for that final kill, but couldn't catch up in time.) ending on 32 kills, 4 deaths and 9 assists. And given his slow start with DPS, easily catching up and overtaking other champions to come top of the DPS charts.

Pros

Extremely easy Jungler early game. No need to worry about health when you can just rotate Tiger and Turtle stance for high lifesteal % with a very high attack speed.
Great for catching up to running champions with Bear stance, running at a speed that makes Master Yi look like a snail.
High damage even with defensive build.

Cons

Very mana intensive early game, hard to maintain a good rotation without blue buff.
No high damage burst skills, all damage comes from Autoattacks
Fairly pointless Ult and not enough skillpoints at 18 to max all skills.

The idea is to start with your hunters machete and full stack of health potions and go wild in the wild. do just over 2 rotations and return at about 1200g to buy Avarice Blade, and upgrade the machete to Spirit Stone. this now nets you an extra +2g per kill, +3g per 10 seconds, 20% more damage to monsters, as well as some health/mana return when they die which will help maintain those stance swaps. About stance swaps, for Damage, simply go into the fight with W (Turtle stance) to gain a barrier, swap to Q for Tiger to get increased damage and attack speed to kill them while shielded, as soon as the cooldown is up, swap back into Turtle to regain the shield, and in the 2 second cooldown left on Tiger, you will get 2 hits in with high lifesteal to replenish any lost health. For the opposite effect, start with Tiger to get the 6 second attack speed boost, then swap to Turtle to get rabid striking healthsteal attacks while shielded.

By the time you hit 6, the buffs are respawning and you should have 2/2/2 for QWE, get buffs, try to hit a 7th level en-route, and with any luck you will still have 2 health potions left, for which you can now take and whoop some dragon *** to help your team with a little gold. Dragon is soloable at lvl 6 as Udyr, so shouldn't be a problem, just make sure to use those extra health potions, smite and swap to the health gain rotation. After this get to ganking.

Go in with Bear, speedboost to gap close, hit-stun, then either swap to tiger for quick burst, or turtle then tiger for a safe burst. By the time you hit 18 Baron cant damage you, so feel free to solo him while your team pushes for a surprise sudden heavy damage boost mid fight.

Just remember to keep an eye on conservation while ganking, pop into the jungle and kill a big beastie to make sure its always kept ticking over, never let it sit on 80. The items in my build are nearly all the highest cost items, so all the gold counts, I rarely get a game to last long enough to buy every piece of my setup.

This is my first build I've felt compelled to share, so please, constructive criticism where necessary. Also if I missed anything point it out.