Caution: Banner Adverts… on your page
If you want to sell ad space on your page, once it has more visitors, make sure, that you stay in control. Personally I don't think that having 3rd party ads on your page is worth the money you get for it - there are some exceptions, but few and far between.
What ever you do: don't let you page be taken over by advertisements or advertisers. This can ruin a good reputation in no time, and the advertiser doesn't care, as he is moving on to the next page to ruin. Host banners from advertisers on your web server or web space. Don't just include a link they give you: You'll never know what is at the other end of that link.
Always remember: You are selling space on your page, and not the integrity of it.
One rule that I have always had, no matter how much I would have liked a banner-ad deal:

Just say "No" to popup-ads!