I've bought several rooted San Pedro's and Peruvian Torch's.
I just planted in cacti/citrus soil I got at the garden center. In a ceramic pot.
Cacti are easy to take care of. they are hard to kill. you can neglect them and they will survive.
Mine have survived a few winters(mild in my area) outdoors, including several freezes.
I've heard they can survive harsher winters than I am use to.
they can be planted outside in the ground if good drainage is provided.San Pedro is faster growing than Peyote and legal.
However once you consume it or prepare it for consumption it becomes illegal. San Pedro does contain less mescaline. So more must be consumed than Peyote.
I would say San Pedro is good for first time cactus growers.
For More info check out erowid
http://www.erowid.org/plants/cacti/cacti.shtml
And here is a cacti related board:
http://www.entheogen.com/forum/forumdisplay.php?f=134 lots of info.