easiest is to checkout the source from cvs, cd to build directory and type 'build docs'
Alternately, download the source tar/gnuzip file from http://sourceforge.net/project/showfiles.php?group_id=22866
filename currently is jboss-3.0.3-src.tgz
Extract the files (winzip works fine),
cd to the build subdirectory,
type "build all"
I found "build docs" and "build doc" do not work with
this particular batch file.
I think this is a little easier than going through CVS if you don't have CVS set up on your system.
Took less than 6 minutes to complete build on a Windows XP machine running about 800 MHz. Does generate a lot of errors, but it seems to be working and I think those errors are all safely ignored.