Below are some of the Mac Museum related links that I visit.
Low End Mac – The premier site for getting the most out of your Mac. They have hardware specs for every Mac released (including current ones) as well as price lists for used Macs, deal trackers, and articles about how to best utilize an older, or even current, Mac. I frequent this one often.
Apple History – Another great site with specs on every Mac.
Mac Tracker – A database of every Mac, it’s specs, and its history right on your Mac or iPhone. This is invaluable when I’m scoping something out a new addition on eBay or Craigslist. It’s really well-designed too.
Vectronic’s Apple World – A great online Mac museum with in-depth articles about their collection. Every article includes detailed photos and obscure facts. They even have a gallery of old Apple advertisements and print materials. A really great site.
Shrine of Apple – Their goal is to artistically photograph every Apple product ever produced. They do a great job at it. They have some really, really obscure stuff that I never knew existed (like the PowerBook floppy disk set). They also include info, but the photos are what make it shine.