The best "tool" I have found to start planning my quilts is called Ladies Art Company Block Tool, [ATTACH=CONFIG]321674[/ATTACH]
these cards have 160+ blocks, does the math for you and shows how to put each piece together to make the block. After you choose however many blocks you like then you use your graph paper or EQ to design your quilt.
http://www.amazon.com/Rediscovered-C.../dp/1571209859 if you check this out you can look thru the cards and get an idea of what I'm trying to explain. Good luck...and have fun!!