Dear Jonathan
The best book of these for the catsailor is in my opinion the ...
Katamarane, Das Buch. von Helge Sach, Andreas Kling. Dsv-Verlag (2002)
http://www.amazon.de/exec/obidos/AS.../sr=1-1/ref=sr_1_0_1/302-5694732-2727224It gives you all the information about modern catsailing including racing and spinnacker handling.
The other books are more for the beginners.
Greetings from Switzerland, St. Gallen
Andi