a few beginner git questions

[Thomas Anderson <zelnaga@gmail.com>]

A few questions.

1. When do you commit changes and when do you stage changes?  Or maybe
more to the point, what's the difference between doing "stage, commit,
stage, commit" and "stage, stage, commit"?

2. What's the difference between merging and pushing?  In CVS, you
merge code by manually adding changes.  ie. the CVS client doesn't do
the merging - you do.  Yet in Git Gui, there's a Merge menu button, as
if it's now supposed to be somehow automated?

3. Creating branches in Git Gui is easy enough but it's unclear to me
how to switch back to the trunk once you've created a branch.

4. I clone git://github.com/symfony/symfony.git to c:\git\test\root
and clone that to c:\git\test\clone.  I then blank
c:\git\test\clone\README, stage it, commit it and push it and the
change does not appear in c:\git\test\root\README.  I then reopen Git
Gui and open root and there I see the blanked README as an uncommited
state change.  I commit it and the change still does not appear in
c:\git\test\root\README.  Is this what Git should be doing?