Hey NS,
My hunch is, a number of people could still learn a few things (and maybe a lot)about the boot fitting process. Boots are the most important component to your setup, so you should probably know your stuff (whether your in the market for your first pair of boots, or you tenth.
These articles were written by Charlie Bradley a senior boot fitter at The Boot Doctors in Taos, NM.
The 101 article discusses the myth of half sizes and issues of selecting the right shell length. The 201 article talks about boot sole length; why Mondo sizes have changed over the years; custom foot beds (the importance of identifying the right type - rigid or flexible); and an explanation of the stance balance alignment (or "canting") process. It's good stuff.
The 101 article:
http://blistergearreview.com/gear-101/boot-fitting-101/boot-fitting-101
The 201 article:
http://blistergearreview.com/gear-101/boot-fitting-101/boot-fitting-201
Enjoy, you might learn something.