Using a virtual environment is highly recommended, although this is not a must. Using virtualenvwrapper can isolate your development environment. You will be able to work on the latest datanommer from git checkout without messing the installed datanommer copy in your system.
Install virtualenvwrapper by:
$ sudo yum install python-virtualenvwrapper
GitHub supports several lightweight markup languages for documentation; the most popular ones (generally, not just at GitHub) are Markdown and reStructuredText. Markdown is sometimes considered easier to use, and is often preferred when the purpose is simply to generate HTML. On the other hand, reStructuredText is more extensible and powerful, with native support (not just embedded HTML) for tables, as well as things like automatic generation of tables of contents.