Provided is a list of useful sites, as well as some questions to keep in mind as you research -
http://www.maicar.com/GML/index.html - Myth Index; primary sources
http://www.pantheon.org/areas/genealogy/ - Edith Hamilton - Encyclopaedia Mythica
http://www.loggia.com/ - Mythography; background information and some legends on all major gods
http://www.theoi.com/greek-mythology/olympian-gods.html - more myths and information, artwork of gods
http://en.wikipedia.org/wiki/Greek_mythology - Wikipedia overview on Greek mythology
REMEMBER - Think of the god you are researching IN THE CONTEXT OF ANCIENT GREECE, which means you will also have to do some research on Greek history.
For example, if you are researching Poseidon, it will be very useful to understand more about how Ancient Greek society relied upon the ocean, because this will inform the way the god is "shaped."
