If you haven't started yet, Jaybird Quilts did a quiltalong on this last year. Her cutting instructions are dead accurate and worth reading:http://www.jaybirdquilts.com/2010/04/hexagon-quilt-along-cutting.html
Read all of the quiltalong posts and she'll walk you right through it, start to finish.
My own advice: I found it easiest to use my own 6x24 ruler and the 60-degree mark. Also, don't mix-and-match too much: the nicest results for this style of quilt (in my opinion) come from a single block done in coordinated fabrics.