www.llrx.com has updated its guide to the federal legal system. A nice thing about the updates at LLRX is that they highlight the changed sections.
There is a link to a PDF file describing the U.S. federal court system. It’s available not only in English, but also in French, Russian, Serbian and Turkish (what, no Croatian?!)
There’s even a link to a tutorial on researching administrative law, which is more than I need myself.