a) not sure I understand your question? carpet is up to you and purchased locally, along with padding. get what you like.
b) can't help, never used curtains.
I assume you know you need "side" surrounds, but using rears will have to do with how close you are sitting to the rear wall to justify getting them. You normally want some room between the sitting area and the speakers.
to post a picture you put and image tag in front and end of your path and file name. A lot depends on where you host the picture. If your using photobucket, just copy and past the image tag. otherwise use the format
[img ] file name and path [ /img]
make sure you remove the spaces...