Use TagIt to assign tags and ratings to your files. If you already have Fresh then you won't need Tagit. To tag a file - just drag it onto the Tagit application in the dock. You can also assign ratings. Tagit lets you drag multiple documents to it at once. With multiple documents, Tagit will add tags to all the documents, leaving individual tags on specific documents alone.

Requirements:
OS X 10.6.5+
Intel