From what I've seen, I'd wet sand and start around 240 or 320. Then on to 400, 500, 600, and 800. I'd top it off with 1500 or 2000. To polish, I use Mother's Billet metal polish.
I sometimes will start sanding perpendicular to the edge with one grit and when I move up in grit number (or down in grit size), I'll switch to sanding parallel with the edge. This lets me know when all the previous grit's scratches are gone. It's easy for a deep 240 grit scratch to hide when you only sand one way only to show up when you start polishing.
My 2c. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />