These are links to things I find useful – note that I do not check these very often so beware, and of course I have no responsibility over anything those sites might do to your computer!
Me!
Baluns, un-uns, toriods and such
The twelfth-wave matching transformer
G0KYA’s long wire and un-un info
Random wire antennas
The “Best” Random Wire Antenna Lengths
Calculators and info