Shooting Illustrated has a good article about maintaining your 1911s. This article was again written by Sheriff Jim Wilson who wrote the defense holster article below.
Some tips:
Cotton swabs are good ideas
Every 1000 rounds, you should replace recoil spring, clean firing pin and extractor
A few drops of lubrication, not too little, not too much
Magazines are a plenty, so replace those that do not work.
From: Shooting Illustrated