Can I recommend this one?
Mark is going to list it when he gets around to it... for a first venue, it's perfect in my view.
Hxx aka The Birthday Girl
Although not strictly only for swinging, I quite like Rio's.
Especially for a first timer, it can be a good place because you don't have to go there Just to Swing, so that you don't feel left out if you don't feel like joining in. Many people go just to enjoy the spa facilities.
If you don't want to be fending off single men, couples night would be a good idea. Although in my experience, the single guys aren't too bad at Rio's...as long as you are firm (not rude) about saying no, if necessary.
there is a great atmosphere at the couples zone parties - ideal if u want to keep your clothes on and watch -
or theres a new club at alexandra palace