There are some sample .gitignore for eclipse project out there. However, if you are doing a google appengine eclipse project, don't use those .gitignore. The easiest thing is to include .classpath, .settings/, and .project in git for the appengine eclipse. That way, when you import project, it will still work.
However, your version of appengine jars may be different. So you may want to change the jar files in war/WEB-INF/lib/