I have a teacher (Jeff Woods) that introduces me to many more rhythms than I can glean from YouTube. Many west African and world rhythms have been adapted to Conga drums, and sound great. However, I don't know of a DVD or CD to recommend. The Congabook has some of what I mentioned and a lot more that I haven't learned yet. YouTube can range from masterful to not so good but is definitely a great asset. I know that I have only scratched the surface since starting lessons last fall; but, what I have learned, I know I know it, and my hands are always ready to play on stage with other musicians.

I am up in the mid-fifties as far as the number of distinct rhythms that I have at my disposal, only because of my teacher...I think no matter how good at searching the web or working from books or CDs, starting with a teacher has put me years ahead of where I would be otherwise.
As far as working from a paper transcription of a new rhythm, it is only hard at first and then once your hands have worked it out, over the next few days keep trying to do it slowly with a metronome for about 10 minutes at a time. The initial goal is to be able to recall it by name and play it correctly at any time without looking at the transcription, i.e. no crutches. I often am tapping out new patterns on my (oversize) belly as I fall asleep at night, working on drilling them into my heart. Discipline pays dividends. When on your drums, focus totally on the sound of the strokes and the melody of the open tones, leaving speed off the table completely. Then think of songs it might sound good with, get them on your iPod or whatever, and play along with them. Start with songs that are slow enough to let you execute the rhythm under control and with all tones sounding right.