The Help section of Fitbit's website has a printable manual for the Fitbit Zip. In addition, third party sites such as ManualsLib also have manuals for the Zip.
As of 2015, the manual on the Fitbit website is in PDF format, providing a document that you can easily print or reference on a personal computer. The version of the manual on the ManualsLib website has a single Web page per page of the manual, which is harder to print, although it is more interactive and searchable. The table of contents has hyperlinks to each page of the manual, allowing a user to instantly jump to a particular section.