Mark,
Welcome to the forums and to one of the best...if not the best CMS!
I suppose you are using Wayfinder for your menu? It has a parameter called &level that determines how deep the menu should go. If you specify &level=`0` or don’t use the parameter at all, Wayfinder will display all levels. If you want to limit the number to say, 3 levels, you would add that to your Wayfinder call, e.g.:
[[Wayfinder? &startId=`0` &level=`3`....etc, etc]]
The documents and their parents have to be published in order for them to show. They also have to have their "show in menu" boxes ticked (seen when editing the document). By the way, there is a way to tell Wayfinder to still show in the menu a dcoument who’s "show in menu" box is unticked...but that’s for your homework and another day
This site is your best friend for things Wayfinder:
http://www.muddydogpaws.com/development/wayfinder/features.html
Oh, and I think the e-book in my sig might be of some use...
Have you managed to find other MODx tutorials/resources? If not I’d be happy to post them here for you.
cheers/k
ps: ex joomla guy...