Newbie falls at first hurdle

I have been lurking on this mailing list since the beginning, but have just got to the point where I want to use git to manage something I am doing.

I have already got a working directory (or rather a directory hierarchy) of an application with files (combination of html and java), and I need to start applying some control to it. The Tutorial unfortunately does not cover this case. Nevertheless I have proceeded.

So at the top-level I have done 'git-init-db'

but I now assume I have to add all the files to the cache

So 'git-update-cache --add *' would seem to be the next step.

However this fails with a message 

error: JavaSource: is a directory fatal: Unable to add JavaSource to database; maybe you want to use --add option?

Since I am already using the --add option, I really don't understand what I am doing wrong.

Help please.