You might need the Logitech Control Centre software. I seem to remember that it was required in earlier versions of Mac OS X and came on a CD-ROM with the mouse when purchased. I don't know if it was specific to the model of mouse or a generic driver. Have you looked on the Logitech website? I suspect that from OS X 10.4 and later there is not a need for a separate mouse driver because I bought a new Logitech mouse just yesterday and it is plug-and-play for 10.4 and above.
The Logitech Control Centre is a System Preference that allowed actions to be assigned to the mouse buttons and scroll wheel.
Hope this helps,
I'm trying to get a Logitech G5 USB corded mouse to work with Mac OS 10.3. The strange thing is that the mouse pointer moves on the screen fine, but the mouse buttons don't register at all. Any ideas?