I spent a lot of time finding out that user settings are on:
      http://ostorybook.tuxfamily.org/user.php

However, there is no link to these settings, would it be possible to add one (for instance near the "Logout" button) ?

The right way to go to the user's preferences is:
- select Log out
- select My account
- go down and select Modify

Yes, it is a little bit complicated, but it is the normal way for this Guppy CMS.

OK, thanks. A little "Windowish" - with the "Start" button
Guppy should at least change the default button label Even "Account" or "<username>" would be more intuitive than "Logout", IMHO...