how do I save the extra files that come in a dmg? After I download a DMG to my Mac and install the apps that come in it, where should I keep the miscellaneous other files (like Readme and license terms) that come in the DMG? I want to keep them, but where, and how do I keep them associated with their app? Keeping the entire DMG just for its little misc files seems wasteful of storage. What is the normal practice?
Personally, I create a folder within the Applications folder with the same name as the app installed from the DMG and put the extra files in that folder. That way, they're always side by side and I can easily find them.

That, of course, is just personal preference. There is no strictly correct way of doing that.