Typing accents and special characters on your Mac

Tonight I needed to type a square root symbol when I was taking down some notes  — ?

I had no clue now to do this.  Then I found a website that shows you how to key in math symbols, accent marks, and other special characters (Euro, British Pound, etc).

This is a site to bookmark:

http://tlt.its.psu.edu/suggestions/international/accents/codemac.html