I\'m new to programming and am trying to set up Ruby on Rails using Michael Hartl\'s tutorial via Terminal on a Mac running Snow Leopard, but I\'m a bit stuck on this part.
/Users/CZom/.gemrc should be a user specific config file that gets loaded when executing the gem command. Sounds like in your case it is a directory instead. Rubygems is complaining therefore.
Try to rename /Users/CZom/.gemrc or remove it completely if it isn't needed.