When you’ve found a good topic for your paper, you want to look for sources that give you reliable and true information. Your best bet is to look up specialized encyclopedias and dictionaries, or ask the reference librarian.
‘Great,’ you think, ‘I just check Wikipedia.’ Well, first of all the authors of the entries may or may not be experts on the topic. Secondly, anybody can edit the pages, anytime. Wikipedia can be a good source to quickly look up a topic, but always use other sources, as well. It is your job to find dependable and true information. Did I mention that you can ask the reference librarians in your library for help?
But if you insist on doing it yourself, you may want to look at several criteria, such as authority, currency and accuracy of the information, the author(s) point of view, the coverage and value of the information. This link explains it further with examples (2 minutes): http://www.youtube.com/watch?v=cWnm7GmeG74&feature=related
Now imagine you got an assignment to write a paper about cephalopods, and you came across this great page http://www.zapatopi.net/treeoctopus .
Would you use this website for your research paper?