I heartily recommend the Gillete book for new lighting designers (It's commonly used as a college light design 101 text). The new edition is like $80... but don't panic. I found a used copy of an earlier edition for $7. The theory is all the same they just updated some of the technology... you'll be just fine with an older copy. So search amazon and other used book sources.
Just go right to the source, USITT. I keep this in my lighting notebook at all times. It's an excellent resource. It even has the new LED symbols and a symbol for a "cym unit", which is obviously targeting the Seachanger.