It is important to evaluate the websites you use for your reserach. To evaluate sites, consider these criteria:
Purpose: What is the purpose of the site? To inform? To persuade?
Authority: Who is the author of the webiste and what are the credentials of that person or entity? The author may be an individual or an organization.
Timeliness: How current is the information? Can you tell when it was last updated?
Scope: How deep is the website? Is it within your range of comprehension? Is it too simple? Is it too technical?
Cite Seer. Digital library for computer and information science literature.
Energy Citations Database. Access to citations and full-text articles from 1943-present in various science fields.
NASA. National Aeronautics and Space Administration.
Science Accelerator. Documents from a wide variety of publication types, moderated by the Department of Energy.
Science Research: A free, publicly available deep web search engine that uses advanced "federated search technology" to return high quality results by submitting your search query - in real-time - to other well respected search engines then collating, ranking and dropping duplicates of the results.
Scitopia. Digital library of 21 leading science and technology societies.