"SECOND TEMPLE SYNAGOGUES" is a cool website owned by Donald D. Binder. It includes the full text of his book Into the Temple Courts: The Place of the Synagogues in the Second Temple Period (Atlanta: The Society of Biblical Literature, 1999), an image gallery of Second Temple synagogues, and many other goodies. I don't have time to profile his library of resources in detail right now, but I'll try to say more about parts of it later.