Thanks for the welcome, guys!
After reading up a bit more, I think the first big problem will be my almost complete lack of knowledge about basic practical electronics. (How basic, you ask? Well, the red wire is plus on a battery, right?) Interestingly enough, I had all the stuff like resistors, logic circuits, and Ohm's law in school, but it was completely theoretical. Which tells you a lot about the German education system, as good as it is.
So I've gone out and bought myself a little "Digitale Elektronik" experiment kit for 15 euros -- not much more than a 4 x NAND chip, a flipflop and a bunch of LEDs and resistors, but enough to get me stripping wires and plugging things into a breadboard (
http://www.conrad.de/ce/de/product/1922 ... ik/0418047). The idea was also that if it turns out I hate this sort of stuff, I'd better find out before I invest in any serious equipment (turns out it's more fun than I thought, so no worries there). Building something with a pull down resistor, however small and silly, makes the concept much more real.
Speaking of equipment, that will be the next problem. I have a general multimeter, but I figure I'll need a serial-to-USB connector, an EPROM programmer, a power supply, stuff to wire-wrap, and an anti-static mat at some point -- anything else? None of it looks too expensive for the basic models, but I'll be spreading it out over time.
Lastly, thanks for the tip about starting small. I actually found myself thinking about grand stuff like a keyboard interface and some sort of display before I realized that the first step should be a 65c02, a chip for serial access over a terminal, some memory, and whatever glue chips. If that works, I can always build a second, more complex one.
For the next few weeks, I'll be sticking to putting the right resistor before the right LED and wiring flip-flops together while reading more and learning how to actually do stuff. Oh, and thanks again for the great info here!