Is there a way to print a bunch of files at once, say, those grouped in a folder?
Put a shortcut to your printer in the Dock. Select and drag one or more documents and drop them on that printer shortcut.
To put a printer shortcut in the Dock, you open System Preferences > Print & Fax, click-hold a printer in the printers list, and drag the icon to the desktop. This will put a shortcut to the printer on the desktop, which you then drag into the dock, where it will stay permanently if you wish. OS X (rather, 10.6.6) doesn’t let you drag the shortcut directly from the printers list to the dock.
You need to drop printable files on the dock printer (RTF, PDF, Text). If your printer driver doesn’t recognize the file, it will have OS X open the editor for that file type instead of printing. If you drag a group icon from DT to the printer, the printer driver will offer to print a list of document names, but won’t print the documents inside the group. The File > Print command in DT will merely print a listing of the selected file names if you use the command on a selection of more than one document. YMMV - some printer drivers might not act properly as Dock printers.