You have many options when it comes to selecting a program to manage your citations; view the columns below and the tabs above for more information on specific citation managers.
All citation management programs let you:
For more information on a variety of citation managers (EndNote, Zotero, Mendeley) and more, including step-by-step exercises to get you started, see the Library's guide Manage Your Citations
Charts like this Literature Review Matrix (.doc) help you organize what you find in your literature search. (This is a simplified version of the matrix presented in Health sciences literature review made easy: the matrix method, J. Garrard; Sudbury, MA: Jones and Bartlett Learning, 2011)
Using a spreadsheet is an alternative approach.
You can adapt Zotero, EndNote, or Mendeley to be used with a matrix like this by using notes or custom fields in your database.
Nearly all the databases you use to find articles, etc., retain your search history for the duration of your session.
Literature reviews, like all research, should be rigorous and reproducible. Save or print your search history to help document your search strategy, which should include:
PubMed's History (click "Advanced" under the search box) and My NCBI can help with both saving your search strategy and the citations you find in PubMed. See the PubMed Tips guide for more information. Other databases have similar tools to save and/or download search history.