You can clone with
HTTPS or Subversion.
There are various resources available, depending on the type of help you're looking for:
For getting started and general documentation, please browse, and feel free to contribute to the project wiki.
For support questions ("How do I", "I can't seem to", etc.) please search and if not already answered, open a thread in the Support Forums.
For technical issues (e.g., to submit a bug or feature request) please search and if not already filed, open an issue on GitHub.
For implementation, and all general questions ("Is it possible to..", "Has anyone..."), please search, and if not already answered, post a topic to the general discussion list serve