Begonias enjoy lots of bright indirect light, but no direct sun. These can grow in artificial light like fluorescent, although experiences vary. 
Let the top of the soil dry before watering again. They enjoy a good soak, but need to dry out mostly between watering.
Although Rex Begonias like humidity, they do not like being misted. Because of their textured surface, molds and mildew can form if the plant leaves are overly wet.
 Available in a 140mm pot.