There are 3 different rule sets I am aware of outside Codex
rks. Ferals, Klans, and KoS.
These rule sets give Orks alot of Flavor, imho the best in the game outside of Spacemarines (for their imapct on flavor, nothing else).
I personally don't like the Klan rules, as I find them too restricting, so I went KoS. Mucho Fun.
Another option is to simply call them "insert Klan" and use the vanilla codex lists.
In any event www.the-waaagh.com is the best place to go for orky advice. There is an anti-stupid setiment going through the ranks right now, specifically aimed at newer people. There have been a couple of really really big tools latley. The point is, think your first few posts through and you should be fine.