I know just how you feel - been there, got the T-shirt etc. But perhaps today is your lucky day, ’cos I’ve just about got my own draft of notes on Ditto up to the point where I don’t mind other people seeing them. Link below. Give me an hour to upload what I’ve been doing today, though.
Before you go there, please note that Ditto v2.1+, the current version, is part of the standard installation of MODx 0.9.6.3. So, unless you chose to leave it out during installation, you already have it, no need for downloads, snippet creation etc. Just look in Resources > Manage Resources > Snippets and check Ditto is listed among them. If you did exclude it, and you haven’t done much yet by way of creating material you want to keep, it might be simpler to do a re-install of MODx than work out snippet creation. I think you get the option to ’upgrade’ when an existing installation is detected.
My notes are intended to update the excellent roundup of Ditto 2.0.1 by myfriendscallmebill,
http://modxcms.com/forums/index.php/topic,13533.msg88741.html#msg88741, which I have found enormously helpful. I am producing them in the context of a site, with examples, because I find that a worked example is by far the best way of describing how complex things work. The site will be featuring some aspects of front-end content production and management, based on my recent experience updating another site.
Notes are here (still plenty to do by way of both content and format):
http://www.pogwatch.com/ditto

KP