You can find a copy of the manual for the Pfaff Hobbymatic 917 on ManualOwl.com for free.
Other places might have it too, but this is the only one that I know for sure does have it. You can also check out U-Manual.com, SewingMachineManual.com and the Pfaff website itself to see if they have it available.
While you're at it, I think it might be a good idea to register your Pfaff Hobbymatic 917 with Pfaff themselves so that they will keep you up to date with any new information about your sewing machine or any deals they may have on parts etc that might be helpful to you.
Also on the Pfaff website, you'll find lots of cool project ideas and step by step guides on how to make lots of useful items for your home.
The 'inspiration' tab is definitely somewhere to check out if you have a Pfaff machine and an internet connection.