Don't place anything adhesive on the machine and do not use cleaners on it. The old style of finish on the machine can be damaged, for example, by placing adhesive tape on the machine (or any other adhesive to use as a guide for seam allowances). New cleaners can damage the finish and remove or change the color of the decals. If the machine needs cleaning, one of the best ways to do it is to use sewing machine on a soft cloth and just wipe the machine down. Soften heavier dirt by leaving the oil on for a day or so before wiping off.
Since you purchased the machine, I would also highly recommend purchasing a manual for it. Does not have to be an original; can be one of the newer care guide manuals. These provide lots of instructions and pictures for care and maintenance purposes.
Edit: Here are free manuals you can download and print:
http://thefeatherweight221factory.com/page7.php