Besides assigned readings in the text, there are a variety of places you can go to find additional background and/or interpretive material on the texts we'll be talking about. Here are a few suggestions:
The headnotes in the Longman Anthology are generally good, and I recommend reading any that apply to the assigned course readings. If you have relevant Norton Anthologies lying around, they too generally have good headnotes for the authors and time periods about which we'll be reading.
Chadwyck's Literature Online provides a great deal of background information.
Study guides can be found at Cummings Study Guides and SparkNotes. Wikipedia also frequently has good background information on authors, historical topics, and (often) individual texts.
Journal articles on relevant topics let you see the scholarly discussion about relevant texts. Journal articles can be easily found through Google Scholar, Project MUSE, an article search at the UCSB Library website (be sure to check the options for their advanced search), the database collection available through the UCSB library (the MLA international bibliography is a good place to start), and JSTOR.
Texts we'll be reading this quarter are now out of copyright, which means there's a fair likelihood that you can find a good copy online (though you should be careful about evaluating whether it really is a good copy, and citations of printed versions are always preferable on course papers). Good places to start looking include Project Gutenberg, The Open Library, and the Internet Archive's Ebook and Texts Archive.
You are also (of course!) welcome to come talk to me about any course-related topics that interest you in my office.
Keeping track of what sources you've consulted in doing research is important, whether this is done by keeping notes in a word processor document that includes URLs and dates of access, note cards, or specialized software. Personally, I use and recommend Zotero, a citation management tool that integrates with the Firefox web browser.
Some of the sites above require that you log in through the UCSB library proxy server (using your U-Mail username/password) in order to access them. This is an indication that these are sites paid for by the Univeristy for your benefit — you should take advantage of this while you're a student and have the opportunity to do so!
Please feel free to suggest other resources that you think belong here.