Good advice above, but for total newbies, some more specific tips are probably needed. Showing someone in person (as in HITCH, good flick) is best, but how to sum it up in writing? A bit of drumming theory might help. Sorry if the following is ugly.
- For most techno dance music, there are four bass beats or pulses per bar. That is, one two three four, one two three four. Identify these beats and count them.
- For R&B, rock, break beat music, it gets more complicated. But all you have to do is find (a) the phat bass beat and the (b) snare drum beat. So it goes one (bass) TWO (snare) three (bass) FOUR (snare), one TWO three FOUR. The emphasis is on the snare beat.
- Some techno can also have a snare sound that goes with beats two and four. But essentially treat all four beats the same.
- In each case, try to move your feet in time with the bass beats (techno) or the bass and snare beats (rock, R&B, break beat). Just do that, nothing else. Even do this sitting down and tapping your foot. Feel it? You've found the the rhythm or what my drum teacher called the 'groove'.
- On the dance floor, lift and drop your feet like this: one (left) two (right) three (left) four (right). Yes, just like marching!
- Once you're comfortable with that, try moving your hand or arm at the same time as your feet, or to every second beat. Just do a small movement, something that feels natural. Normally this is when a crowd would clap or some dude on headphones rocking out would click his fingers.
- Now that you know how to find the groove, you can improvise other movements: drop your shoulders, nod your head, etc. Try different combinations. You don't have to be John Travolta or MJ.
- I learned a lot by watching other people dancing, and by taking note of pro dancers in music clips.
- Once you get your basic technique nailed, you can add extra steps between beats: one AND two AND three AND four. This means you're putting mini-steps in between the main beats. I do this for a few bars, then switch to normal speed, pepper a few mini-steps in here and there, etc. Great fun.
- I need about 30 mins warm up. Before then, I am fairly stiff and uncoordinated. A few drinks help, too. And comfortable shoes that don't grip the floor. Being able to slide your feet makes it much easier, otherwise you have to do discrete foot stepping movements.
- Me personally, I hate dancing to rock, but can do it if I'm with a group. I don't mind R&B but usually can't get into it unless I know the songs. I much prefer dance/techno/trance music for dancing. You may have other preferences.
Good luck!