Polishing rims from Bandit Alley, the Bandit forum, by "the roamr":

I just did my rims. I left the tires on, came out great. I used aircraft paint remover bought at an Auto zone, $4.99 a can [aerosol], took about 3 hrs to do both rims. I didnt use anything but the stripper. No need, every bit of paint came off. I only had to leave the stripper on for about 3 min per area, and wipe with towel, worked great .Be aware the front rim is slightly more difficult for the paint to strip [dont know why] A few days later I used some aluminum polish to see if they would shine up a little better, and it helped some, they were shiny to begin with. To use an abrasive I think would compromise the finish unless your stripper isnt working and there's no other way to get it off. I do recommend using a tape to cover the strip in the middle of the rim and to cover the tire right near the rim. Youll want to use a tape thats not water soluble, so to repel the stripper. It will eventually seep through the tape but by then the stripper is losing its acidity.

Did anyone do anything to protect against the elements? What I do is keep 'em clean and dry. I polish them with metal polish when I wax the bike.  If you have Brasso, you could use that. I've used Duraglit and Nevrdull on them (cotton wadding with polish imbedded in - also popular brass polishing products used by military folks). Lately, I've been using stuff Holeshot sells-Magic Metal Mix (or something like that). It works well, too.