Yep, you've come to the right place there. Just remember three things:
1. There are LETHAL voltages in there. One touch to a 500V wire may send you directly to the morgue.
2. Building amps by hand ain't cheap
3. While they may sould close to the originals (as my Mesa Mark IIC+ does), they'll never sound exactly the same unless you have original output transformer (expensive). On the other hand, they may sound BETTER than the originals as well.
As a rule, if you're going to build more than one (and you ARE, even if you think otherwise), build a separate power amp, preferably with Baxandall (two knob) EQ in the input stage. Initial cash outlay is a bit larger (need two power transformers instead of one) but you'll reap the benefits later on. Plug in another preamp (or POD, or PODxt) and you're ready to rock.
For the first prototype use a deep cake pan. If you REALLY want to know how stuff works and how to improve it (without getting Ph.D. in EE first), buy "The Ultimate Tone" book from www.londonpower.com
One more advice - don't get into this if you're trying to save a buck or two. This is an EXPENSIVE hobby (of my hobbies only photography is more expensive), costs add up like you wouldn't believe.
Sure, you end up with "one of a kind" piece of equipment, but the end result depends on how good you are at this, so for a beginner the result can be quite frustrating, especially with high gain amps. My first amp was quite playable right from the first power up, but I got tired of it pretty quickly and re-built it into 2nd channel of Soldano X88R which I still have. And I did have a lot of experience in semiconductor electronics prior to building my first amp.
Ask yer questions, I can answer whatever you want to know.