How to Write a Literature Review
University of North Carolina at http://www.unc.edu/depts/wcweb/handouts_pdf/Literature_Review.pdf This is thorough and requires Adobe Acrobat to read because it is a pdf file. A read-only version is online at http://www.unc.edu/depts/wcweb/handouts/literature_review.html
The Literature Review: A Few Tips on Conducting It" at http://www.utoronto.ca/writing/litrev.html - short and to the point
from U. Calif Santa Cruz - http://library.ucsc.edu/ref/howto/literaturereview.html
Univ. of Wisconsin - http://www.wisc.edu/writing/Handbook/ReviewofLiterature.html