Toyota Repair: 99 Toyota Tacoma Prerunner, toyota tacoma prerunner, stop signs

Question
130K miles, auto transmission. When in a stopped position & in drive, then stepping on gas, the truck will not immediately move.  Then will clunk into gear and start accelerating. This doesn't happen only when going from park to drive, but at stop signs and stop lights also.  Are there any simple (i.e. inexpensive) things that can be ruled out or does this sound like a serious transmission problem?  Appreciate any advice.

Answer
Check the transmission fluid with the engine warmed up and at idle, if the fluid is low add as necessary and check for a possible leak at the transmission, if the fluid is not low and smells kind of burned then I would suspect a major transmission problem.