It could be a starter problem, but from your description there"s no guarantee that the starter solenoid is working properly -- just because it clicks, that doesn"t necessarily mean it"s connecting the big "in" cable from the battery to the big "out" cable to the starter.
According to the archives, a starter will sometimes lock up. You can release it by loosening the starter mounting bolts, wiggling the starter a little, and re-tightening the bolts.
If that does not work, I would recommend you make sure your battery-to-ground connection is excellent (so you know it can carry the current required by the starter). Then, with the transmission in neutral and the brakes locked, connect the non-grounded battery terminal directly to the starter input with a jumper cable to see if it turns over. If it does, suspect the solenoid or maybe some cable corrosion hidden under the insulation. If it still does not turn over, then itís a pretty good bet the problem is with the starter.
Mark W. in MI