How do I get my Orchids to grow and blossom?

I was given a few Orchids, 1 that had already boomed and the other 2 were just the leaves. Now all are just the leaves and I can't get them to grow and blossom. This is my first attempt at having Orchids. My mom has many and they are always in bloom. I have tried everything she has told me, but, I am having no luck. I need help.