http://www.trombone.org/jfb/twooctavescales.asp
this should keep you busy for a while. if you are good with key signatures, you can learn them that way. that`s how I did it. or you can go by half-step/whole-step patterns as well.
unfortunately, there is no shortcut... it takes a lot of practice and repetition to make them second nature.
if you are really serious about trombone and want to try to wrap your brain around some serious theories about learning scales, shoot me an email, and i`ll hip you to some articles by Joe Jackson, lead bone and band leader of the USAF Airmen of Note.