A good quality iron (30W to 60W, variable temp and regulated temp helpful but not required).
A solder sponge or wire wool pad to keep the tip clean.
Good rosin-core 60/40 or 63/37 solder by a reputable company (Kester or Multi-Core).
Some wire and some terminal strips to practice on.
Some YouTube videos.
Lots and lots (and lots and lots) of practice.
All of the above will make for a less frustrating experience.
It's really not hard once you get the hang of it, but it is critical to learn correctly to begin with.
"Art of Electronics" Horowitz and Hill . Not much math but explains virtually everything you need to know . 2nd edition is 20+ years old but still very useful, and $35 instead of $80 (3rd ed.) .
Perhaps a little overkill for someone just starting out, but one of the best college texts on the subject of electronics ever written. Ever! Really.
Something a little more approachable to start with might be any of the armed forces technical manuals on electronics. The department of the navy published Basic Electronics, by Dover, which is pretty simple and complete. Also seek out Electronic Techniques: Shop Practices and Construction by Villanucci/Avtgis/Megow.
Others' suggestions to build some cables or a pedal kit are right on target. Cables, especially, are easy to make and easy to re-do as he gets the hang of it and makes some beginners' mistakes. And who doesn't need extra cables?!?
EDIT: I just looked up Electronic Techniques on Amazon.... $245! Yikes!!! Find an old, used copy for 25 bucks. Mine is 3rd edition - they're up to 7th. Hand soldering hasn't changed much since about 1965. I'm pretty sure an older edition will work just fine!
