Council of British Archaeology - Great starting point
The BBC History Zone - An extensive sites that has done much for the promotion of Archaeology
Internet archaeology - the first internet journal created, very extensive
Aerial Archaeology Research Group - all you ever wanted to know about aerial archaeology
Clwyd-Powys Archaeological Trust - Local group
English Heritage - Do I really need to expain?
Archaeology on the Net - Comprehensive site
Insitute of Field Archaeologists
Personal Research Sites:
Virtual Museum of Nautical Archaeology - Great site covering a wide and up-to-date range of topics
Underwater Archaeology - Good guide to Underwater Archaeology on the net
AGI - Company specialising in GIS