There is excellent documentation on MaxL that Oracle provides. It is located here.
If you like working from the command line, you might prefer MaxL to EAS and Workspace because there aren't any mouseclicks involved. Secondly, you are connecting directly to the Essbase Server, so that makes it all that much faster as well.
Raam is correct that you can automate tasks using MaxL. For instance, if you have four calculation scripts that you need to run in a row, you can forego kicking them off in EAS sequentially and instead write a MaxL script that runs them all in a row for you.
Another benefit of scripting the process is being able to take advantage of some nice logging features Essbase in a directory that is convenient for you instead of buried deep within the Hyperion or EPM system directories.
However, since you're new to Essbase, you should know that MaxL does not provide all the functionality you have in the Hyperion Planning and Workspace UIs. There are command line utilities for planning and workspace, but they are not based on MaxL.