If you have a decent background in trasistors, or just general electronic basics, look at garage sales for what really are old correspondence courses, but they were usually by different authors. Look through some old Popular Science, or Popular Mechanix magazines from the fifties or sixties, invariably you will see the titles to look for, and there were many.
Old book stores likely have a good selection of those same books too. Boy scout manuals are also a good reference.
Also, looking through some fo the old posts on this forum can be of assistance, as well as just searching the web.
Also, if you are looking for designs and theory, check out Lindsay books
http://www.lindsaybks.com/
And the Crystal set society:
http://www.midnightscience.com/bookstore.html
The latter is good if you thought that crystal radios could only recieve the AM band (MW), they have many plans. Theory is covered quite a bit too.
: Looking For a good resource for learning antique radio repair. Anyone have a good place to start my quest
A good starter book is "Old time radios! Restoration and repair" by Joseph J Carr.
It can be bought at www.tubesandmore.com But I think I bought mine from one of
those large franchise bookstores.