Charlie Parker at the Open Door is a must - wild blowing by Bird. I have it on an Ember 2 CD set (though it could have fit on one CD). I'm not sure how it's available these days, but the recordings are definitely worth seeking out.
Jeff has already commented on recordings with Red Rodney in 1949-50. I'll just put forth one specific recommendation from that period - recordings from Birdland in 1950 which were available on Royal Jazz - Charlie Parker: More Unissued Vol. 2. They may have been issued elsewhere as well. Fiery, fiery playing by Bird, Rodney, Kenny Drew, Curly Russell. and Art Blakey - not to be missed.
Charlie Parker: More Unissued Vol. 1 on Royal Jazz has two recordings done with Bird,Lennie Tristano, and Kenny Clarke (playing on a phone book). If you're a Bird fanatic, it's worth getting just for those two cuts. Also available on Philology.
Finally, I'll mention three cuts that have Bird sitting in with the Stan Kenton Orchestra on Bird's Eyes Vol. 8 - Philology W80.2.
Fine stuff, plus that CD also contains an interview done withPaul Desmond and Bird in 1953 or 1954. The interview is perhaps not essential (though I guess it is to me), but it's interesting.