2000 Dodge Dakota Starter, solenoid or both?

Recently have had problems starting, turn key and get only a single click sound, after several attempts it usually starts. sometimes I go weeks without a problem then it happens and usually continues for a couple of days or longer. What does this sound like to you guys? I understand that a flat spot on the starter is a possibility but thought that when starter was going it would emit a steady clicking noise (continue as long as the ignition is held forward). Any help would be greatly appreciated, Thanks.