Electronic Projects and Electronics Tutorials: An electronics tutorial radio design site. A page that covers nearly every conceivable subject of RF design and construction; with tips, hints and advice.
Harry's Homebrew: Antennas, home brew radio circuits, and some theory.
How does a RF receiver work ?: How do radio receivers manage to communicate over huge distances? An explanation of the fundamental mechanism.
How Radio Works: Informative multipart tutorial with illustrations and animations explains everything about radio waves, many related links.
Octaloop Antenna: A gif schematic of a 8 sided antenna with mount details.