Working with the fhm_tray extension installed is pretty straightforward and not very different from the usual typo3 workflow. The main difference is that editors do not see the whole frontend tree, but only their unique roles. Inside those roles are trays. By clicking on a tray and then on “Edit page header”, users can verify the “rootlines”, eg. where in the frontend articles will be published that they write.
To write a new article, click on the name of the tray you want it to be published in. Click “New page” as you first have to make a new blank page to write your article on. Then fill this new page with content elements.
For more info take a look at the Help section of our website (mostly german, though):
http://www.fh-mainz.de/index.php?id=2495&E=1