New to Photography, With a Minolta

I received a Minolta Maxxum QTsi, from my father (his old one). I have been using it to take pictures of my son, during his sports. What my question is, where to go to find telephoto lenses for this? Can you use lenses from different cameras on this on? Which ones would be compatible. It currently has the stock 35-80mm lens on it. I appreciate any help anyone can give. just remember, I am pretty much a newborn at this.
Thanks! Mike

Mike,
Any Minolta "Maxxum" or Konica-Minolta "Maxxum" lens will fit your camera. They are usually tagged "Minolta AF" lenses. I don't think the newer Sony Alpha lenses will work on your camera, but I'm not sure on that.
Companies like Sigma, Tokina and Tamron have made lenses for your camera also. Make sure when purchasing your lens that it fits 35mm cameras or Full Frame Alpha cameras.
No lenses from other brand cameras (Nikon, Pentax, Canon, etc.) will fit directly.
Minolta AF lenses are not hard to find. You can get them almost anywhere. New and used. Keh camera (web), B&H Photo (web or store), Unique photo (web or store)and even ebay.
Minolta cameras are good cameras. Enjoy it.

Thanks for the info Jim. I will definately start looking around.