Over at Xavier's great website, he's got an article on shopping for 1911's and the things to look at and watch out for. It's a great article: Checking a Used 1911 with a Purchase in Mind. X's taste in handguns runs similar to mine, so I always find his gun related posts very interesting and well written. X could certainly be writing for a handgun magazine, his posts and articles are that good.
Spend some time going through his archives and posts over the past few years about various guns, pawn shop gun shopping and all sorts of gun related lore. It's a great read, and I spent several weeks in my spare time reading his previous gun posts (he also posts about photography and other subjects). Although I consider myself quite knowledgeable when it comes to handguns and shooting them, as well as law enforcement use of sidearms and concealed carry, I've learned lots from reading his past posts. I've been carrying a gun (legally, I'll add), for several decades now, and was an avid handgun shooter by 6th grade, and avidly reading about guns since that time, but even this old dog can be taught something new about guns by reading X's site.
I know quite a bit about handguns, so I enjoy reading X because he's generally right on the money and he knows more about a lot of handgun subjects than I do. I've learned a lot reading his site.
So if you're contemplating a purchase of a used 1911, read this post. If you're looking for a new 1911, you should do a lot of reading to find out who is making the most reliable pistols out there now. There are a ton of 1911 variants being made and sold, and many have some questionable or cheap parts in them, called MIM. Opinions vary about MIM parts, but I'd prefer to spend a bit more up front for a quality 1911 instead of having to pay for the parts later on as well as the gunsmith fee to install them.