AutoCap Version 1.0 - An autotuner project specifically for small transmitting loops.
An Overview of the Underestimated Magnetic Loop HF Antenna by Leigh Turner, VK5KLT
AA5TB Small Loop Site - includes an excellent Excel calculator for sizing loop components.
Magnetic Loop Antenna Calculator - an alternative web-based calculator.
ARRL Antenna Book - Source for the formulas used by AA5TB's design spreadsheet.