Substituting Gluten Free Flour

I'm experimenting with making gluten free muffins and was looking for gluten free flour substitutions equal to 1 cup of white or wheat flour.  I found this GREAT chart on Karinya's website .

FLOUR (To replace 1 cup of flour)	AMOUNT TO SUBSTITUTE	FLOUR (To replace 1 tablespoon of wheat flour as a thickener)	AMOUNT
Amaranth flour*	1 Cup	Agar(Kanten)	1 1/2 tsps
Barley Flour*	1 1/3 Cup	Arrowroot	1 1/2 tsps
Buckwheat Flour*	7/8 Cup	Bean Flour	3 tsps
Corn Flour	1 1/3 Cup	Corn Starch	1 1/2 tsps
Corn Meal	1 Cup	Gelatin Powder	1 1/2 tsps
Garbanzo (Chick Pea) Flour	3/4 Cup	Guar Gum	1 1/2 tsps
Kamut Flour*	7/8 Cup	Kudzu Powder	3/4 tsps
Millet Flour*	1 Cup	Oat Flour*	1 tblsps
Nuts (finely ground)	1/2 Cup	Sweet Rice Flour	1 tblsps
Oat Flour	1 1/3 Cup	Rice Flour	1 tblsps
Potato Starch Flour	3/4 Cup	Rice Flour (Brown/White)	1 tblsps
Quinoa Flour*	1 Cup	Tapioca Flour	1 1/2 tblsps
Rice Flour* (Brown/White)	7/8 Cup	Quick Cooking Tapioca (Pre-cooked)	2 tsps
Rye Flour*	1 1/4 Cup	Xanthan Gum	1 tblsps
Soy Flour	1/2 Cup + 1/2 Cup Potato Starch Flour
Spelt Flour*	1 Cup
Sweet Rice Flour	7/8 Cup
Tapioca Flour	1 Cup
Teff Flour*	7/8 Cup		* Avoid if gluten sensitive