Wouldn't it be great if you could read other people dissertations (at other schools) for their bibliographies and works cited?
Dissertations and Theses Full Text (read PHDs and Master's Degrees for style, content and their bibliographies)
Usually, the most cited articles in a field are the most influential.
Go to an Citation Analysis database (different ones for different disciplines).
The impact factor is a measurement of how influential a journal title is by measuring citations. Detailed explanation here.
Here's how you get the impact factor.
Go to an ISI Citation Analysis database (different ones for different disciplines).
After you find a citation, look over to the right.
Which then takes you to this screen.