Can anyone suggest to me any sources of research, like sites, books or magazines on global warming for my research paper?

One place to start is here:
http://blogs.chron.com/sciguy/
This is the blog by the science editor at the Houston Chronicle, and he frequently writes about global warming/climate change. You can scroll down and look on the right for earier posts; be sure to click on the Climate Change category, too. You can also search this particular blog for posts on this topic.

The reason I'm suggesting this blog is because he frequently refers to specific people and their research on this topic. If you post a question in the comments of one of his posts, and be sure to put your email address in there (which won't be printed, but will give him contact with you), he can help you further if you need sources for research.

=)