I'd suggest you come up with some terms of business before you start the work to cover you incase things get a bit tricky. For example - you'll provide 4 layouts, two revisions before the build and once design has been signed off there will be additional charges incurred for design changes. Clients will sometimes try to see how far they can push you, if you're just a friend/freelancer in a way that they wouldn't do if they were dealing with a larger company so it doesn't hurt to state what's what before you start.
Work out an hourly rate, think about how long you think it will take you (a couple of days I dare say) and multiply the two. I think charging between 300-500 for a small static site is fairly reasonable.
Bear in mind that if you're hoping to get referrals from it, you'll need to make it not only attractive but make sure it complies with web standards and you do a good job of the SEO too. Not to mention, since we're at it, that it's cross compatible with IE and firefox at the very least, but you should really test in opera and netscape as well.
It's very easy to throw together something in frontpage (*shudder*) or dreamweaver and call yourself a web designer but there's a lot to take into account to make sure you do a good job of it. If you need some help, have a look at
http://www.w3schools.com/ for tutorials and ask about on the forum there as they're usually pretty helpful.
Good luck.