Rippetoe's stuff is pretty good. The first book on why barbells and getting started:

* https://www.amazon.com/Starting-Strength-Basic-Barbell-Train...

After a few months you'll exhaust that (perhaps just take it out of the library?), and need more intermediate-level information:

* https://www.amazon.com/Practical-Programming-Strength-Traini...

Otherwise, some others have suggested a few Reddit threads; see also /r/fitness.

I've really enjoyed Mark Rippetoe's writing about the difference between Exercise and Training.

From the gloss for Practical Programming for Strength Training [1]: "Exercise is physical activity for its own sake, a workout done for the effect it produces today, during the workout or right after you're through. Training is physical activity done with a longer-term goal in mind, the constituent workouts of which are specifically designed to produce that goal."

He emphasizes that a realistic means of progression is one of the most important aspects of any training program.

Practical Programming and Starting Strength [2] (which is a better introduction to these ideas for novices) are together the best analytical discussion of physical training that I've seen.

[1] http://www.amazon.com/Practical-Programming-Strength-Trainin...

[2] http://www.amazon.com/Starting-Strength-3rd-Mark-Rippetoe/dp...

His book Practical Programming is also good if you want a slightly more advanced take on the subject. It still has a chapter going over this beginning workout and why it makes sense. Even though most people don't need the advanced training programs, it's damn interesting to read about the science behind them.

http://www.amazon.com/Practical-Programming-Strength-Trainin...