When I first tried MODx Revolution (which I did try before MODx Evolution) I found the documentation to be pretty good except about snippet syntax. The tag syntax has changed from MODx Evolution to MODx Revolution.
[Wayfinder? &startId=`0`]
has to changed to
[[Wayfinder? &startId=`0`]]
More information can now be found here for all of the tag syntax changes.
