What's the Best service manual for a 200 Ford Ranger?

Though I would have answered "the Factory Service Manual" previously - I now have one (on CD) and it's cryptic and almost unusable. I also have the Haynes manual. Also not good.

Trying to troubleshoot a cold starting issue that I think is timing-related.

Where can I find a good explanation about what sensor does what and how to test them?

Added (1). What is the "Best" service manual for a 2000 Ford Ranger?

2001 Ford Ranger clicks once then won't turn over, and when key is turned off, it begins making a clicking relay noise under the dash? - 1

I've had this happen before, and the last couple times I just undid the battery and put it back in and it started right up. The battery has a charge, the alternator is new, and I tried jumping the battery just in case. So I know it's not that. I'm thinking it could be something in the ignition switch because sometimes I have to lift up on the shifter knob for it to register that it's in park and turn over. Any ideas?

Should I get a newer truck?

I have a standard 4x4 86 Ford ranger. It has a 2.9l v6 with 350,000 miles on it and 4 speed auto. It is starting to have issues and needs new tires. For me to fix it I would cost about 1,000 in parts and another 1,000 for tires. I'm wondering if it's time to get a new truck or just try to fix this one.

Transmission won't shift?

The automatic transmission in my 1994 Ford Ranger won't shift. I can put in gear but it won't engage. I have changed the vacuum modulator. As well as changed the fluid and filter making sure I was at the correct level. Any idea what could be going on? The engine is 3.0L there are approximately 180k miles on the original transmission. I don't know enough to really troubleshoot what's going on. Would like to fix it myself or at least try before taking it to the shop. Any help is appreciated -thanks