SEO for flash websites is something we have been waiting for for a long time. Truth is Adobe Flash is not SEO friendly. The best idea would be not have a 100% flash website. Try keeping flash for some elements of your website like just the banner (by the way you can use jquery for the banner, there’s lots of free fantastic scripts out there.)
Well if you really cant get away from flash, its best you optimize that one index page you have (thats if you even have an index page)
Add a proper title and description that describes your entire business and service in a few words as possible. The only other thing you can do beyond this is get lots of links coming to your website. You could either exchange some with friends or buy some links. Buying links is…bad good advice; it might get you ranking or get you booted out, so be very cautious. One other thing i would recommend is creating another website designed with an seo friendly CMS. Get content on the site and the link to your flash website. Then check Google Analytics to see if your SEO site is getting more traffic than your Flash site and if this is true then maybe you should consider switching to SEO completely.
If ever possible, dont go the 100% Flash website way. Try maybe jquery. And if only your menu is flash animated in your entire flash site, consider having the rest of the content outside flash.
There are ways to optimize a flash website, but im anti-flash at the moment