I have the 2 in die that i love... and you need to 'cut' your fabric before your place it it on the die.. you only need to cover the blades not the entire length of the die itself..
Ebony has this awesome website.. check out how she Outlines the dies to eliminate wasted fabric.. and she has some really awesome tutes..
http://quiltpossible.com/
oh yea, buy mats, buy extra mats- they are disposable so to speak, as you will soon find out..