Usually when a client ask for just a website design to be done I'll provide them with a compressed folder with the following:

• JPEG Previews of All Image Files
• Photoshop Layered Documents
• Illustrator Files
• A complete set of fonts (if you are to use a commercial font it's best to clear things over with the client to either make arrangements for the to purchase the font as well or you simply don't provide it within the folder).
• Personally I also like to write up a little thank note inside the folder that has contact information, and a detailed descriptions of the project.

On the other hand if it is a complete website I won't provide then with the Photoshop documents or layered files (.psd) unless it's requested by the client initially. Sometime I'll charge x amount of money to release them. That usually depends on who will the work will become copyright to.