I assume named after the desert and not the small dog. Very solid plants with thick leaves and please symmetry. An easy plant to grow which will bloom for most of the summer months with attractive yellow and orange flowers.
Echeverias are drought tolerant plants that will survive for quite some time without water. You don't need to rush out and water them every five minutes but, the more you water the bigger and more luxuriant they will become. A general liquid feed given a couple of times during active growth will also be benificial.
All of our plants are grown in multi purpose compost and allowed to dry out between watering. As an alternative they can be potted into a free draining soil based compost.
Echeverias require protection over the winter. All of our Echeverias are grown in unheated polytunnels with minimal watering during the colder months and they easily survive the winter. Alternatlively if you live in a colder area or just want to enjoy them through the winter they will be more than happy on a sunny windowsill.