Sometimes you may want to change the permissions of subfolder and all of there files. This could be down to the simple need to enable them to be read only for part of a server network or in my case allowing files and subfolders and files to be read and write for website development. Its took me a while to figure out how to do this, and it is blindingly obvious.
If you right click on any folder or file and select Get Info you will see a pane of information as you would expect. If you then click the pad lock and enter your admin password you will be able to edit the folder permissions at the bottom.
The problem with this is that it only changes the folder you are on. This can be a real problem if you have hundreds of files and folders that you want to enable specific settings, you would have to go through each one and change it by hand. The solution is to click on the tiny cog at the bottom of the pane, almost hidden away.
Clicking Apply To Enclosed Items will set the permissions to what you have changed above to every single item. It will come up with a warning message saying if you want to change them or not. Click OK. It will then whir away for a couple of seconds based on how many files and folders it has to change and then you will be done. If you want to change them back simply change the permissions in the list and apply it to the items once again.