Find a high impact journal to publish in using Journal Citation Reports (JCR)!

Another measure is Eigenfactor.  This same site calculates "Article Influence."  Here are some quick descriptions of the two.

SCImago Journal Rank is yet another measure and is used in the database, Scopus, which is similar to Web of Science.

This page was created by Nancy Linden and modified by Suzanne Ferimer.

This is a great overview from NC State on the topic.  Read this before starting your thesis or your next paper!