A/C Woes in TEXAS!

I drive a 1996 Passat V6, and it seems like my blower motor needs a good kick in the butt, or a possible replacement:
It works fine for about 20 minutes, then kinda fizzles out.
(It still runs, but just doesnt push any air through the vents...)
When we shut the car off for a little while, and restart the car, it kicks back on..

Questions:
Could this be simply a blower motor resistor?
Is it more likely the actual blower motor needs replaced?
If so, can an amateur with many tools replace this, or should i leave it to a professional?

Whatever needs to be done needs to be done fast since it's my wife's ride.

Thanks much.
-Brett