This article covers a more friendly way of using the chmod command instead of trying to memorize ugly mode strings!

$ chmod -R u+rwX,g+rwX,o+rX *

What this does is set:

• user permissions: u+rwX (read, write and directory traversal or execute for files where something else has set the execute bit)
• group permissions: g+rwX (as above)
• other permissions: o+rX (read and directory traversal) 

I've used them put together here and comma seperated however you can use them individually, so to just set other (not user or group):

chmod o+rw filename

Please note if not exactly specified it will apply to all (user, group and other), e.g.:

chmod +rw filename

Gives user, group and other read and write access to the file. -R is used for recursively setting permissions over directories and their contents. In this example I've also used + to add the values to files that might not have it. We can use - to remove that permission and = to ensure that it all equals those permissions.