how to sell rights to a picture...?

[dilario.livejournal.com]

First off, I'm really sorry if this kind of thing has been posted before! I did a quick search and didn't find anything, so I hope I'm not repeating anything.

So, I was recently approached by the owner of a nightclub regarding a picture of mine I did a few years ago of a personal character. He wants to buy the rights of the picture so he can turn it into a large sign for the club to be displayed out on the wall of the entrance. I checked everything out and it is legit (he sent pictures and I found the club website, and the nightclub is snazzy as all heck!!). The picture itself is completely white/red/black, like a vector image, and would probably be fairly easy to reproduce. I'm totally up for this idea, and I'm quite excited about it, but I haven't the slightest of how to go about selling him this. What kind of things should I ask? Anything I should expect? How much should I ask for or expect for an offer? :C I am so lost! Any and all advice would be super helpful!