I wipe the outside of mine down,
I clean the bobbin area out about every other day.
I take a q-tip, dampen it with a little machine oil, and use that to get the lint out. Just twist the head of it down tightly, put a drop or 2 of the oil on it and the lint will grab on to it.
My repair man said to not use canned air, especially if you have a machine that has any sort of computer in it. OR...just not use it at all. It will blow stuff deeper in and/or moisture will build up inside your machine. If you have the nozzle too close and spray, moisture does come out...not a good thing.