I don't yet have a lock, mainly because I don't know which one(s) to get. Years ago, I had a bike that I'd locked stolen while I was in the library for 15 minutes (Glendale, California). Today, I finally figured out a route to the library here in Palmdale, rode the Downtube there, and before I could fold it up, was told that I couldn't bring a bike in the library, whether it folded up or not.
Before I go back, can you all recommend a lock or locks? What's the best way to lock it?