You can pick up any of Giovanni Hidalgo's instructional videos, he will amaze you time and time again.  I have an Alex Acuna video were he plays both trap and percussions, he's another great teacher, and Richie Gajate-garcia has some good videos as well.

I got started with a Ritchie Gajate-Garcia Tape after I bought my first conga.  It taught me some of the basic stuff I am still using today.  Tumbao. Clave. 4 against 6.  Good stuff.  I would also recomend getting a teacher to personally teach you.  I think I am learning more each week with my conga teacher than I learned through the video.  Nothing compares to actually being there.  (but the vid did get me started)