Online Resources:

http://eserver.org/

http://vos.ucsb.edu/

http://ipl.org/

http://humbul.ac.uk/

http://www.LitEncyc.com/

http://www.oed.com/

Now, another important point in terms of research: LIBRARIES.

For instance, by becoming a member of the British Council, you get not only the chance to borrow amazing books/texts from their resposite, but also an electronic account, which affords you the ability to use multiple databases, in all fields of interest.