Hello BelenIT,

Here is the complete Guide and setup manual for the Printer.

http://support.dell.com/support/edocs/systems/prn3115c/

Let me know if this is the one which you are looking for.

I do not know of a place that a comprehensive guide is posted. If your warranty is still valid Dell will provide best effort support to assist you with the setup. Alternatively, you can ask the agent you reach if they can provide you with some documentation.