First off, your "main page" does NOT have to be named "main.html." I did that for a very long time, until the idiocy of it struck me. Name it a keyword. If it's a black site, call it something like "black-sex.html." Anything that will get more keywords into the site you're creating.
This site will be constructed simply:
Three banners
Your title or logo
Some keyword laden descriptive text
Your gallery links
We're going to discuss this a little out of order, per usual.
The gallery links. Now, calling them "gallery 1" and "gallery 2" may be accurate, but it gets no keywords into the site. Neither does calling those pages "gallery1.html" and "gallery2.html."
We'll pretend we're making a "black sex site."
Name the gallery pages "black-sex-pics-1.html" and "black-sex-pics-2.html" (Or "black-porn-1.html" or whatever your little heart desires. Remember, these pages aren't going to be submitted to anything on their own, so the names can be as long as you want. Make sure there's a hyphen before the "1" and the "2," though, or it will confuse the search engines.)
The links on the main page should be called "Black Sex Pics Gallery #1" and "Black Sex Pics Gallery #2" or whatever. That not only gets in more keywords, it makes the links bigger and easier to find. (Linkmasters like that part.) You can also put unlinked text about your pic gallery links, describing what the pics are about. It gets in more keywords and it makes sure the surfer will stick around on your site, thus seeing your banners.
Don't waste your time making graphics to link your galleries. They pull the eye away from your sponsor banners and you don't EVER want that.
Make sure your gallery links are in the same size font you use for everything else. Don't cheat and make them tiny. You won't get listed that way.