Wired’s newly-revamped Webmonkey site has an informative guide on seeing, changing, and understanding file permissions in Unix-like systems. These are the kind of operations and syntax that can often confuse and put off first-time Linux users or command line neophytes on OS X systems, but Webmonkey details the commands you need to change permissions on however many files for whichever users you need. Worth a bookmark, and a good work-around for those unexpected “Action not permitted”-type errors.