The second editon of the Student Manual for the Art of
Electronics (or
whatever the exact title is) has a set of experiments which get you to
construct a very simple 68008-based device. The book describes making it
on solderless breadboards, but obviously you could solder or wire-wrap it
if you prefer.
It's probably not a bad starting poitn if you've never built a computer
from scratch before.
I still wasn't able to find this book at a fair price in Brazil. As soon
as I have some free money I'll get the art of electronics and the student
manual from USA :oP