For accurate reporting, you will need to keep an accurate count of the number citations you find in each database, the number of duplicate citations between databases, and the number of citations removed in each phase of the screening. Reference managers ike RefWorks are essential for keeping an accurate count, and they can make the removal of duplicates much easier. The PRISMA flow diagram can help you to keep track of citation numbers at every stage of the review process.
Keeping track of your search strings increases reproducibility. Many researchers publish their searches as a supplement to their systematic review, so it's a good idea to keep a record of every search string. This tracking spreadsheet from MD Anderson's Research Medical Library will help you to store your search strings and database information.
The slides below will walk you through key tools and considerations for the data extraction phase of your review: