Having just followed the installation instructions for installing v3.121 of MT, the instructions explain how you get to the weblog configuration screen.
At this point installation guidance ends: The next step is to access the weblog I have just created, but there seems to be no documentation on how this is achieved.
Guessing on what the URL might be leads me to an index.html file containing the following text:
Movable Type
You cannot view the contents of this directory.
If you are installing Movable Type for the first time, look at the Installation Instructions
Rereading the install instructions, and looking through the main docs, there seems to be no record of where MT publishes content to. The docs only refer to accessing the configuration section, but not the weblog itself.
To fix this, a piece of documentation needs to be added after "Running Movable Type" called "Accessing your Weblog" with some basic instructions on how to access the weblog once configuration is complete, along with possible reasons why your content may not be found.
It is probably the most basic task of the config of any weblog, and is probably incredibly obvious to someone who has configured a weblog before, but to a new user the lack of a hint as to where to find the resulting weblog is frustrating and time consuming.