Free detailed guides to soldering can be found at the following sites:
- Sparkfun: https://learn.sparkfun.com/tutorials/how-to-solder-through-hole-soldering/—a well illustrated first users guide to soldering
- Adafruit: https://learn.adafruit.com/adafruit-guide-excellent-soldering—as the title suggests, this guide shows how to do excellent soldering
- The Basic Soldering Guide by Alan Winstanley is an ideal place to learn more about how to solder and extend the skill you've started to pick up in this chapter. This goes into great depth about the tools and types of solder.
- Make Electronics: Learning by Discovery by Charles Platt: I've started to cover some basic electronics, such as shifting logic levels and timing diagrams. To get a real feel for electronics, Make Electronics is a superb introduction.
- Practical Electronics for Inventors, Fourth...