Not sure why you are saying it isn't well documented. I'm a newb too (at least to Linux) so I just googled it and came up with this
on the first page of the search.
I used to run the "updatedb" command when I was using the "locate" command a lot more. But these days I figure if "locate" isn't keeping up with what I am doing I'll just run the "find" command and use some of the operators that I'm now learning to speed things up a bit.
Hope this helps.