This is a very select list of available article databases. If you want to look for others, go to this page and click through to your discipline (political science, sociology, history, etc.). Here you will find a selection of the most useful databases for each discipline listed.
New electronic journals are popping up every day, so I will not include many links here. To find electronic journals accessible from UCLA as well as journals freely available on the web, go to the UCLA Library's e-journals search. You can search by keyword or exact phrase, such as "American poetry," or you can limit by subject area.
ProQuest, the company that published Early English Books Online and LiON, has put together training guides for both resources. If you'd like additional training on how to use either, please check them out.