I'm glad the book A Guide to the Star Wars Universe was brought up. I had the 1994 edition as a kid, and its backstory information was always something I considered to be credible. Often I've found myself continually baffled by some of the outlandish theories about early SW history, and I forget that it's because not everybody grew up reading that book and absorbing its information. I think it's about as good a look at what the world of SW is all about as you can get that hasn't been contaminated by PT and SE changes.

Combine that with some specifics that Zahn introduced in his earlier stories, and you get a very different look at SW history than the altered, 'official' version. It's also a much more interesting universe by far.