HI.
For designing web pages, here is a good article that looks at the basics of separating presentation logic from business logic.
http://www.cs.usfca.edu/~parrt/papers/mvc.templates.pdf
The general feel of the paper is that you have to work quite hard at it because there are many subtle ways that you can fall into mixing business logic with presentation logic. However, there are beneffits to separating the two.
Cheers, Jay
