Books - Online
History of the Franks by Gregory of Tours (Northvegr website)
History of the Later Roman Empire by J.B.Bury (Bill Thayer's website)
Icelandic Saga Database
Roman Britain by Dio Cassius (Bill Thayer's website)
The House of Ptolemy by E.R.Bevan (Bill Thayer's website)
Northvegr - using the links on the right, you can access a wealth of online resources.