Magazines and Publishers on paper and web

• American Radio Relay League
• Antennex (lots of antenna modeling stuff)
• Buckmaster Publishing(Callsign Database)
• eHam.net
• Ham Radio On-Line Magazine
• Hard-Core-DX.com
• QRZ Communications(Callsign Database)
• THE 59(9) DX REPORT
• The Daily DX (Internet DX Bulletin)
• EA7JX QSL cards 
• LZ1JZ QSL cards
• Contesting.com
• eHam.net
• QSL.net
• QTH.com
• ePanorama.net on Radio BIG list of links and references on the web their main site has lots more topics.
• Radio-Electronics.com collection of general radio/electronics info and well organized book list.