Have a look at this overview, a pdf file containing a sketch which illustrates how the pieces of paraslash work together. Read README for general information (including a list of required software), INSTALL for installation notes, and README.mysql for instructions on how to use the mysql database tool shipped with paraslash.
The various commands of para_server and para_audiod are explained in paraslash's manual pages.
As of version 0.2.10, the source of para_server and para_audiod is fully documented. Have a look at the Paraslash API Reference.
Finally, you can RTFS online.