Early game I rush for Devourer and ravenous hydra. They both give AD like crazy, and they both give their own unique buffs. I generally start looking into boots after that, with AS being a huge thing. I build Items with both or one. When you're done with boots, I go on to Situational items. I like to either go into expensive huge damage items, or Tank AD stats. If you're getting bullied by some good ganks on you, I would run AD because running is not an option with Udyr. He can't run away but he can stop an enemy from running. So the idea is to kill them before they kill you. The way I like to do this is with Death's Dance, It spreads damage as a 3 second bleed, allowing you to leech life with Tiger to Turtle so you don't die. If it's impossible to not die, it gives you the chance to kill them off before you die, it's like a 3 second long Sion passive.
The other items will help with killing, but anything that gives 65 AD or more, I would grab. The reason I run AD Tank is for lasting longer in fights, but tank isn't a huge thing I like, as armor is hard to come by in an AD item, but Health isn't. I grab warmog's for health regen when running between lanes, so I always appear with at least 75% health. Sterak with DD is just OP, You get Sterak's near death buff with DD's 3 second don't die, it's a guaranteed kill.
Sterak also gives Scaling AD so that's great for earlier, but once you hit late game, I would start trading out Tank AD for AD only.

I take my skills the way I do because it's the easiest way to kill everything. I take a point in what I need as it comes. I like to have Tiger for killing easier, Turtle for lifesteal, Bear for stuns and MS (Bear stance allows you to run after and stun your target, it's OP AF if you know what you're doing), and then Phoenix so that if you end up trying to delete minion waves using Rav Hydra, you get extra AOE. Sometimes, I like to get tiger as far up as I can, put a point in turtle so I can max tiger and then continue with Turtle and Bear and the Bear and Phoenix. Phoenix is only used for one situation only, minion waves. Otherwise you're screwed.

The general idea is to Tiger on big guy, and then use leftover Tiger AS by switching to Turtle so you can hit faster and get lifesteal from the smaller ones. I find this method to be better, as it allows you to get life back, unlike Phoenix, where you just kill them. This method allows for ignoring potions altogether, as they are just a drain on gold. I would never grab potions unless the top or bot laner(s) don't want to leash. In that case, check your mid laner before giving up hope. I personally like to kill Gromp and then take Turtle stance so I can get blue buff and then go for wolves and continue down. I use Raptor camp as a very good source of life, as the little guys die easily and you can leech health pretty easy. If you want to do an extremely easy way to hit 6, Krug, then raptor, then wolf, then gromp. recall, and kill krug to red buff to raptors to wolves to blue buff to gromp, and thats level 6.