Ø Go to Site Actions, Site Settings
Ø Click Site Content Types
Ø Click Create
Ø Give the new content type a name such as "Description"
Ø Set the parent content type group as Folder Content Types
Ø Set the parent content type to Folder
Ø Add the new content type to a Group. I put it back in the "Folder Content Types" group
Ø Click OK
Ø Scroll down to the columns section and click Add from new site column
Ø Name the column and set all the usual column options
Ø Repeat for any additional columns
Ø Click OK
Ø Go to your document library
Ø Click Settings and Library Settings, or in 2010 click the Library ribbon tab and then click Library Settings
Ø Click Advanced and set Allow management of content types to Yes and click OK (this may already selected)
Ø Scroll down to Content Types and click Add from existing site content types and add your new folder content type
Ø Go to your document library and click the New dropdown, or the New button in the 2010 Document ribbon, and add your new folder!
Ø Go to the View dropdown and click Modify this view and add your new folder meta data columns (you will probably want to move them to just after the Name column)