Do U WaNNa KiSS SoMe OnE...?

Never ask first. Never. Ever. Asking first is just awful. Kills all the romance. Ask about everything else once you really start getting physical. But just don't ask about the kissing part.
But, of course, never kiss someone who doesn't want to be kissed. This is where boys get all defensive.

If you have to lean across more than a foot of space, she doesn't want to be kissed. And anyway, you shouldn't be trying to kiss someone out of the blue anyway. It's like pealing out of a driveway without giving the engine time to warm up. You've got to move a little closer, touch them a little first. Personally, I think holding someone's hand first is a little weird, but some women like that. The all time best thing to do though, is play with her hair. Brush it out of her face. Don't do this while staring intently into her eyes trying to Make A Moment out of it. Just do it casually. Touch her like it's the most natural thing in the world to be touching her. Pay attention: if she retreats to the opposite side of the couch or porch or car well then she's more than a foot away isn't she? No kisses. If she sticks around, keep playing with the hair and go for it.

And don't go nuts with passion either. It's a first kiss--make it sweet and short, 5-10 seconds at most, smile at her and then go back to talking. This is, of course, the description of a date first kiss, you know where you actually like the girl--but it will get you pretty far with one you just randomly picked up too.