you'll need some brass (new, or factory ammo to shoot/reload).
something to clean your brass with - a tumbler.
you also need a little corn cob media, and case polish.
I bought a cheap separator from cabela's also, works great.
does this kit give you a debur/chamfering tool?
you'll definitely need one of those!
check to see what comes with the trimmer too.
you might still need some "pilots", depending on caliber.
dies - check
shell holders - check
still need powder, bullets, and primers.
Should be a very nice setup though - good luck with it!