Use Unilume. Best aluminum polish on the planet.
If its pitted aluminum you have a couple options but strokethis pretty much explained it for you.
Your other option with pitted aluminum is to clean them up with steel wool, shine with polish, dust with flour in a panty ho. It will help cover the black divots in the aluminum.
Other than that just steel wool them and polish away. They make acid washes and brighteners that help make it easier but someone who hasn't worked with them much if at all will end up with dull rims more than likely.