ask Chaosfire

Well, the art of punching things like a bear is ancient and very complex.
Udyr has many build paths, and does not rely on items too much, but there are many items that synergize well with him.
When jungling phoenix, Take defensive boots, depending on their team, Heart of Gold, because its a turtle shell, Wits end, because attack speed=More phoenix procs=More DPS, plus that extra magic damage and magic resist adds up. Phage is a good item, it can be built into a trinity force, or frozen mallet late game. Depending on what you prefer.
If you like Shurelia's Reverie initiations, I take a philo stone after my heart of gold. This is optional, and I'm only mentioning it, because it's saved my life and secured skills many times. When you have your core, (Generally Boots2, Heart of Gold, Wits End, and Possibly Philo Stone,) You want to start getting tanky. If they have a strong ad carry, get a frozen heart or randuins. Thornmail is cool, but the frozen heart reduces their DPS by 20% (The attack speed reduction), and, the Randuins Omen provides similar reduction, as well as other useful stats, such as health. If they have strong AP casters, pick up a force of nature. Lots of Magic resist, you go fast, and health regeneration galore. Trinity Force should be added in there somewhere.
A maw of malmortius is also great if they have more magic damage then normal, plus the AD makes your Trinity procs stronger.
The end build for Phoenix Stance should look like so:
Defensive boots
Wits End
Randuins Omen/Frozen heart
Trinity Force
Force of Nature/Maw of Malmortius
Warmogs Armor/Frozen Mallet.
Other great items are: Aegis of the Legion, Madreds Bloodrazer, if they have many people with lots of HP.
Of course, these are just my thoughts. If you have a system, stick to it.
Protips:
Make sure you have gotten 3 hits off in phoenix stance before switching stances.
Don't forget about your passive, it's not much, but it helps.
Remember that your bear stance stuns anything, as long as you're in the stance, but only once every 6 seconds on the same target. Running around in a teamfight stunning everyone is more effective then you think.
Your focus should always be the carries/assassins on the enemy team. After they have fallen, position yourself to try and hit everyone with your phoenix waves.
As for tiger Udyr, it's worth trying, I personally prefer tiger, but it's a different mindset and play style. I could write some tips for tiger Udyr if you would be interested,

I just don't understand how the enemy Udyr player is always amazing and then your tema Udyr is a pile of shit!

quote Chaosfire

quote Fluroclad

I just don't understand how the enemy Udyr player is always amazing and then your tema Udyr is a pile of shit!

Thats because everyone uses Oddones shitty build from mobafire.
I can vouch for the fact that most udyr's are morons.

Like last night's udyr... Worst ganks I've ever seen. Then the enemy got an udyr the next game and he was good...

quote RazeHell

quote Phoenixmon

Just edited the title

You monster.

At least people actually know what the thread is about ...

quote Eternal

So I'm still new to jungling and need some easy champs to practice with. How's Udyr?

Not sure how correct this is, but udyr is only second to lee sin in jungling.

Chaosfire I don't remember what the tiers were, I just remember reading udyr was apparently number 2.