2000 Ford Ranger pick-up w/90,000 miles, 3.0 liter engine

Initially began with a dead battery and "door ajar" light and dome lights that would not turn off. I removed dome light bulbs and lubricated the door switch(WD-40) and "door ajar light" shut off. After jumpstarting engine, I had the battery checked (it was OK) After truck sat overnight, it would not turn over; starter solenoid clicked. After jump starting again, I had the alternator checked and was told that it was charging the battery enough to produce a 14 volt reading so the problem must be a bad starter. I replaced the starter jumped the engine again and drove truck enough to charge the battery. After shutting off the engine, it cranked immediately. Next morning, starter just clicked. What else could be the problem? I am a novice when it comes to electrical problems, but it seems that there must be a current drain somewhere or there must be a a bad wire in the ignition system. (Although since the engine will crank after being off for a few hours but not after being off overnight, it seems less likely to be a faulty wire). I replaced the battery terminals but am at a loss to know what to do next. Without my truck, I can't work. Although I cannot make a donation right now, I will be able to do so in a few weks Any ideas or suggestions would be greatly appreciated.
Thanks,
Joe Easley