Just a heads up with the book - it's OLD.
A 3rd edition is supposed to be coming out at some time, but it's taking forever. Some basic analog circuit designs are largely unchanged though, so it should still be a good resource.
Another heads up with having electronic components laying around. Make sure to check that the parts are working and have the correct specifications (check your wattages, yo) for their purpose, for safety's sake. You should be able to make a working amplifier from scraps and stuff, but having it run constantly and consistently to your standards might not happen, depending on how strict the design specifications are.
I also want to recommend those sites I posted again, even though you're looking for amplifiers meant for driving speakers. The main thing with the site I posted is that because those headphone amplifiers are meant to be made of discrete components and still be portable, the schematics are much simpler compared to larger and more advanced amplifiers. It can help out a lot in understanding what each portion of the circuit does.
If you're more into the enjoyment of building and soldering the stuff together, there's a lot of amplifier schematics online that you could try making yourself. Just make sure it's safe to do so. I can't name any sites off the top of my head, but there's quite a few DIY amplifiers where the site gives you the schematics, the list of components that you need, and where you can buy it. You usually just buy the PCB from them, and everything else is left to you. It seems like it could be a lot of fun. Sorry I'm not much help there.