DBM 380 Week 5 DQ 3

This file of DBM 380 Week 5 Discussion Question 3 contains:

How do you know when to stop breaking down tables? I get that we want to break parts down to their atomic levels, but all parts? I've read through a few texts about relationals and normalization, but I have yet to find a good set of guidelines on good database practices. As an example I can't imagine have 50 - 2 column tables is acceptable. I also read that one to one relationships shouldn't be combined, yet that doesn't always seem ideal to me.Long story short, do you know a best practices article I could read over?