Here’s a pretty good article with a twist on some pretty basic advice (the psychological factoids).  To add my two cents worth, it’s probably worth noting that all this talk about how great symmetry is doesn’t really work for about 80% of the homes we work on – they simply aren’t big enough, or adequately lit to achieve all this (and lighting is huge deal for your perception of balance).  The best nugget in the whole story, kind of tacked on at the end, is about asymmetrical balance…that’s more relevant for many projects, and especially in smaller spaces.  Harder to understand, harder to do well in design, but much more applicable.  Then, when you really want to geek out, we can talk about how you mix the two…in a balanced way, of course.