Hi Nick,
Welcome to what I think is one of the best tube-audio related sites on the internet. Shannon's ST-35 was my first DIY project, although I had done a fair bit of soldering earlier, and I did not have any problems with building it. There is a lot of chassis work involved, and I outsourced that portion.
Bruce Rozenblit's book "Beginner's guide to tube audio design" is a reasonable book to begin with, I think. It also has a section on the DIY aspect of building audio equipment, and discusses the tools required, component placement etc. It is available from http://www.tubesandmore.com for $24.95.
You might also consider building a kit from Bottlehead first - maybe the Foreplay preamp. The advantage is that you get a complete kit with all parts, and you just put it together. I do not have personal experience with Bottlehead, but have heard only good things about them. See http://www.bottlehead.com/.
Other websites/fora that I visit include Audioasylum and Audiocircle. Lots of good discussions and a great way to learn.
I hope this helps you.
Ashok