In my opinion, the best historical information about the transistor is to be found on the pbs site. This is a non-profit media enterprise owned and operated by the US public television stations.
I'm frequently asked 'what type is transistor XYZ' or 'what modern type could be substituted for XYZ'. Sadly, I often cannot answer because devices in commercial equipment often bore only internal part numbers which were never made public. However, for public part numbers the Web has several sites that document both modern and obsolete types. In my opinion the best of these is datasheetarchive which has a wealth of ever-increasing data, and is even scanning old data books and using them to add vintage devices.
If you are desperate, for devices from several standard series, the part number itself gives information about the type of device.
A friend of mine, Jack Ward, has a Web site devoted entirely to the CK722. It contains a lot of images and information, some of it quite surprising, for example the "transistor within a transistor". He has also developed an extensive online museum of early transistors with many fascinating images and oral histories from people involved in the early industry.
Sergei Frolov has a site showing early Soviet Union transistors and diodes. A good excuse to try automatic language translation. (That's not unusual nowadays, but when I first wrote this page, it was an exciting new application from a site called "Babel Fish").
Mark Burgess, a New Zealander, has a site on transistor history including the Australian manufacturer AWA and European representation of STC, Philips, and CSF down under.
Mike's Electric Stuff shows old advertisements, including some of the first UK transistors and diodes. (Plus loads of other neat and dangerous electric experiments!)
There are so many sites that deal with early transistor radios that it is hard to list any without being unfair to the others, and anyway that is not the subject of my own particular obsession. However, I must mention the magnificent Radio Wallah collection. It has lists of links to many other sites.
Also, Brian Page's "gladly learn" site includes scans of classic early transistor booklets by Raytheon and Sylvania.