valve cover gaskets....

I am having a problem with oil leaking, i got a oil change today and was told they think that my rear main seal is blown. The tranny is covered in oil and i am getting oil on the carb. I was wonder what may be causing this and if it is the valve cover, they are seeping. I am in search of a local mech in another poster that hopefully won't steal my rear end(yes it has been done once).