A good resource would probably be the NSTokenField Programming Guide.
I haven't used token fields before, but as far as I know it's a subclass of NSTextField and the bindings offered in interface builder look fairly alike, so you probably want to bind the token fields value to a string or number, not an array. If you want to get the different strings, you can use NSStrings componentsSeparatedByCharactersInSet: to get the different parts. You can get the tokenizing character set with NSTokenFields tokenizingCharacterSet method. You might have to make some changes to what I wrote since I didn't test this or ever used NSTokenField, so I don't know how good it works.