Basic fundamental hip hop courses? Take a hip hop class -- they should teach you the fundamentals of footwork first, plus a few routines you might like that emulate music video choreography.
Most basic and most important to hip hop or any dance is foot work. Never overlook it ^_^ If you want to work on freestyle, then do as the others suggested, listen to the music and go with the flow. Get used to the way your body moves to certain beats, change it up a bit if it's a rock influenced beat, RnB, Industrial, or whatever.
Pay attention to all the small beats in the song. Nothing looks better than someone who can emphasize beats that you never knew existed by moving to your own rhythm.
Hrm.. what exaclty are you looking for? Club style hip hop or music video? Music Video doesn't translate well into personal style on the dance floor -- some moves can, but for the most part, it looks pretty bad if you try and bust out with a Justin Timberlake routine on the floor, unless you dance at a club full of professional dancers,
then you go to town
There's a competition I danced for about a month and a half ago called "Team Millenia: Prelude Dance Competetion". If you want to see how everyone is choregraphing to these days. You'd be surprised the range of genre's we cover. I'll have to order the DVD sometime soon when I get my next paycheck, and maybe I can rip a few sequences and show you some moves from Kabba Modern, Pac Modern, Formality, Funkonometrey, SickStep, amongst a few others.