<<Disclaimer: Verify this information before applying it to your situation.>>

Cathy suggested the USDA site, and I looked there and found:

chickpea flour, per 100g has 369 Kcal, 22 g protein, 7 grams fat, 4.8 mg
   iron, 45 mg calcium 92g = 1 cup

potato flour, per 100g has 357 Kcal, 6.9 g protein, .34 fat 1.3 iron, 65
   calcium, 160 grams = 1 cup

White rice flour/100g  366 kcal, 6g protein, .35 iron 10 calcium, 158g = 1
   cup

Brown rice flour/100 g 363 kcal, 7.2 protein, 1.9 iron, 11 calcium,
   158g = 1 cup

from my old, battered Laurel's Kitchen, corn flour has about 430 kcal/cup
but if it is Masa Harina (tortilla flour) it's a reasonable source of
calcium

The USDA site is a great resource, I just passed along what I had wanted
to know.  There's even more information there.

Mildred mentioned that Bette Hagman's The Gluten Free Gourmet Bakes Bread
has a lot of flours analyzed by nutritional content.  I haven't gotten
that yet, but it sounds good.

The good folks at Glutino didn't say what was in the flours, but they're
able and eager to provide them!

Thanks to all who responded.  To those who responded that they'd been
wondering too, I hope this helps.

Elizabeth