you only need flash any version will work. its not really possible ot describe how to make a flash site tho in a short response. what you need to do is make a flash project (movie) and make it how oyu want the site to be, and then use the flash embed tags to make it show up in an HTML doucment
Youre gonna need a book or tutorials to make a complete flash site. Id go for a book (you can buy it and return it or get it from the library) since most tutorials just teach you how to make a small flash effect - and not how to make the whole flash site.