i'm assuming since its just a school project, the standards aren't too high...but decent and free rarely come in the same sentence...heres a few illegal ways
supposing you have 0 html skills...get yourself office premium edition (borrow it off someone) and use frontpage from that...messing around with and editing templates will give you a decent looking site fast...but hardly original
supposing you've got some HTML skills, get yourself dreamweaver trial edition, get a keygen and make some codes (i'll give you some if you can't find it)...then you can use it forever...also with dreamweaver you can rip the HTML off some site, replace the background, the buttons, the pictures...and you've got yourself an original website, easy
supposing you've got 1337 HTML skills....i'd be wondering why you're writing this...also you could just code it all by hand in metapad...or notepad if you can't afford the free metapad