StyleSheet is missing — WordPress V 3.0.1

Hi,

I am new to WordPress. I have a theme that I would like to install. When I upload the theme and says Install, I get a message,

“Broken Themes
The following themes are installed but incomplete. Themes must have a stylesheet and a template.
Name Description
4472 Stylesheet is missing.
“

When I searched the folder for a stylesheet, to my astonishment, I don’t have a stylesheet in the zip file. I have downloaded it from “DreamTemplate.com”. Here is a list of files that I have:

agreement.txt
Graph.dot
Graphs.dot
page1.jpg
page2.jpg

Well, I don’t have a clue on how to proceed from here. I am trying to get some knowledge on how WordPress works, but before that if some one can help me out, I would be thankful.