I've just joined internet dating. Any advice?

I'm a 20something ladyshape from the UK. I tried Guardian Soulmates and Tastebuds but they weren't too exciting. This is after about a week. A couple of days ago I joined Ok Cupid. It's different. I've had maybe 100 messages.

Anyone here a veteran of these things? Any warning stories? I've no idea what I'm doing.