Here are your parts.

When it stops can, you restart it right away or do you have to wait for a while?

It sounds like your motor is overheating. It has an internal thermal cutoff which opens and then resets once the motor cools down some.

Could be the motor is just overloaded re: the drum has too much drag for some reason. Try turning the drum by hand, it should rotate fairly easily.
If not open it up and find out why.

Here is a good link with basic info.
http://www.applianceaid.com/dryers.html