How to ride a rap beat?

I enjoy writing rap lyrics and have been doing it for a couple of years now but recently my friend made me think about something when he asked me if "I had any rhythmic skills." I never had really though about it, I usually just write lyrics. I never really put them on a beat and rapped them out loud. I tried it but had a hard time pinpointing exactly how I should "ride" a beat (how say my lyrics to make them sound catchy). I know I have good lyrics, all I need now is to be able to spit them so they sound catchy and have flow. Anyone have any practice techniques, advice, lessons, books, anything? I appreciate it.