Hi A_programmer,

The following URL lists a number of reference texts  for frequency sythesizers:

http://www.am1.us/references.htm

Everyone learns in a different fashion, but if you would like a text that provides a good intuitive explanation, you might peruse the text by Dan Wolaver entitled "Phase-Locked Loop Circuit Design". It is the last  reference listed on the above URL.

There are also a number of tutorials available in Acrobat format at National Semiconductor and Motorola that may be of interest.

good luck!

Shawn