(This plant comes in a 3.5" pot. You will receive a very similar plant to the one in the picture. It may or may not be blooming at the time of your purchase. The plant is shipped in its pot to prevent any damage to the roots).
Most species grow in the shade and can take some frost. Hybrids tend to be less accommodating about their growing conditions. All the species are drought resistant, but they grow better with regular deep watering and fertilizing.
They can be propagated with offsets, leaf cuttings, and if they are not hybrids, by seeds. Offsets is the easier way.
Most species lose their lower leaves in winter. Depending on your level of humidity, these leaves are fertile ground for fungus that can then attack the plant. It is better to remove them regularly. Another consequence is that after a couple of years the plants look untidy. It is better then to re-root the main rosette(s) and keep the rest of the plant for propagation.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz