OK, I'm continuing the slow process of adding useful info such as genus descriptions to the site. I've also added 3 new book reviews and have 3 more on the way:
http://www.cactiguide.com/ref/
New reviews are:
Ariocarpus et cetera
The Genus Turbinicarpus
Rhipsalis & Lepismium
More info being added
More info being added
All Cacti are succulents, but not all succulents are Cacti