To Check Changes Before Actually Renaming
The -n option allows you to check changes before actually renaming. This is very useful, and recommended, as there is no undo button once you have done the renaming!
With this option present, rename will print a list of the changes to stdout rather than actually peforming the changes.
Making All Filenames Title Case
The following command makes all filenames title case, e.g. this is a file.pdf will become This Is A File.pdf.
rename 's/(^|[\s_-])([a-z])/$1\u$2/g' * -f
The -f option is there to force the rename, becuase sometimes it will not recognise the change (for example, when running Linux on a virtual machine and accessing a shared drive on a Windows host).