Git (http://git-scm.com/) is a distributed version control system. It keeps a complete repository next to each working copy, thus one can commit or inspect the project history locally.

Warning: Unlike most other version control systems (e.g., Subversion) a commit is not understood as a difference between two revisions but as the content of its revision. In fact, Git stores the commit under the SHA-1 hash of all files in the project – also files that were not changed in this commit. Thus, the same change of one sub-module committed to two Git branches that differ only in another sub-module results in two different SHA-1 hashes and two different commits. It is possible to work around this by cherry-picking but that will lead to extra headache. Better practice is to have only one feature per branch.

• Pro Git e-book – i can recommend
• git community book – i didn't read
• git crash course for Subversion users
• User Guide for Eclipse plugin
• GitHub Help – you DO NOT need this if you use git only inside Eclipse and are capable to setup a SSH public/private keypair (e.g. on thoas, cp. instructions for linux)