97 Chevy Transmission Problem, Can Anyone Help?

For some reason my automatic transmission hesitates to slip into gear (R,D,1,2,or 3), and then sometimes it will work after restarting the truck. Can anyone Help?

Sounds like a shift solenoid problem to me. Just my 2 cents

Is your "Check Engine" light on? If so have it scaned. If it is showing several codes it could be a malfunction of the ignition switch. Do all of your gauges work? does your speedometer work? GM had some problems with ignition switches that would cause strange problems with transmission shifts and instruments. Since your transmission goes back to working on restarts this could be the case. Just a guess though. If you lose all electrical power to the transmission you will have 3rd gear starts "Limp Mode"

Check your battery connections for corrosion.