You could use this script posted by JohnZeman and modified by Kundal.
I personally use Kundal's three-way button. Left-button to start inserting from left. Right-button to start inserting from right.
Once you have that script/button, all you would need to do is select the files you want to add text, click the button, and type in:
1,author name -
This would insert the "author name - " (the text you typed in) at the beginning of the file names.
If you always want to insert at the beginning of a file name, you could also just use:
Rename PATTERN "*" TO "{dlgstring|Author Name?}*"
@nodeselect
If you always want the " - " to be inserted so you don't have to type it, you could use:
Rename PATTERN "*" TO "{dlgstring|Author Name?} - *"
@nodeselect
Hope this helps.