easily accessible help/documentation

Often, the best (not necessarily easiest, admittedly) way to do this is to have a web browser with tabs open to the documentation for the libraries you are using (doing this method gets easier and much faster with practice, as you can hold more and more of your program in your head).

However, for Python, you could experiment with some of these editors. Just glancing over it, the open source editors Eric and DreamPie and the proprietary Komodo look nice: they appear to offer auto-completion and pop-up documentation, and at least Eric and Komodo have built-in graphical debuggers.