General Info: Cattleya
Cattleyas were once synonymous with the word “orchid.” Now more people equate Phalaenopsis with orchids, but a well grown and flowered Cattleya is a sight to behold. Cattleyas are tropical species that are native to Central and South America. Each species’ geographical range determines its temperature preferences, however most are cool to warm growing. Cattleyas are considered a high light group that need ample light to flower well. In the house, a southern or western window is good, and I suggest growing outdoors in a shaded spot for the summer. People will argue about how much light is enough/too much. I opt for the lower end to keep my plants looking better. Very high light may (possibly) improve blooming but leave you with an ugly plant (in my opinion).
As epiphytic/lithophytic species, these guys are adapted to dry out frequently–thus the fat roots. Make sure that your cattleyas don’t sit with wet roots for weeks at a time. In warm conditions, more water is fine; in cooler conditions, water less frequently. These are plants that do not want to be overwatered. Cattleyas would love to be watered almost like vandas if you have the time and patience: water 2-3 times a week but keep them in little to no media so they dry out in hours.
The American Orchid Society has a number of articles on the Cattleya Alliance. I think this one is a good place to start for cattleya beginners (although there are a few points I would argue about). Chadwick and Sons has a really excellent general orchid care essay, also. If you are new to orchids, definitely read it!