Often, the most difficult part of your research is finding an appropriate topic. There is more information on climate change than you'll be able to read in a lifetime, so you will need to focus your research on an aspect that you can reasonably cover within your time frame. You can try browsing your textbook for interesting topics or do a search on "climate change" in the database Academic Search Complete" and then Refine Results by Subject" listing on the left column.
To find Ebooks, type your search terms, then on the results screen select "Books" under Resource Type, and then "Full-text" online." E-books say "Online Access" so click "View Online" to start reading.