We did this a few years ago. We used a light tint/uv protection on the windows on the south side of the house. In my office we used a darker reflective tint that made a big difference in the summer. The wife put the stuff up, I don't have the patience, I help since the sheets can be big depending on the size of the windows. We used Gila film,
http://www.gilafilms.com/en/Default.aspx