What would it take in the way of materials and permits in the state of
New Mexico to equip a building for the purpose of generating solar
energy solely to feed it back into the electrical grid? I'm not
interested in running anything with the solar power - only in feeding
it back into the grid. I need to know if this is possible, legal, and
all costs associated with doing such a thing.

Just a quick un-scientific comment.
I recently had a bid done to have solar installed on my house. The bid
would be a settup large enough such that essentially I would not need
to draw any electricity from the grid. The cost was roughly 6,000 per
kilowatt of solar settup installed. My settup was for a 3k system (~
18k $) .  This cost includes everything required (solar cells, dc-ac
inverter, frames to hold the cells, etc..). This installation does not
include batteries-- which are not a requirement. To my knowledge (here
in Texas as well...) the electric company is required by law to
purchase electricity that you generate from those cells. I know for a
fact that its true here in Texas., and I think in other states as
well. There is a lifespan on solar cells. Make sure you purchase
equipment that is designed to lasta  long time. Kyocera for example,
has two lines of solar cells; one that they guarentee for ten years,
another that the gaurentee for 25 years. Heat, believe it or not,
causes much of cells demise.