title: how to clone an old git-commit (and some more questions about git)
body: <p>I have a git-repository of my project with about 20 commits. I know how to clone the actual commit with <code>git clone</code>,  </p>
  
  <ul>
  <li>but how can I "clone" an old commit?  </li>
  <li>is there a really good git-GUI (imho <code>qgit</code> is not a good GUI)?  </li>
  <li>what exactly are "branches"?</li>
  <li>when I want to release 0.1, 0.2 and so on, what is the best way to mark these commits in git?</li>
  <li>what are the big differences to svn?</li>
  </ul>