Ok lets see if I can walk you through this.
You will need to know which Family History Center or Library you want the film shipped to which you can find here:
Call them first before ordering your film to make sure they are close to you and have a suitable microfilms scanner/copier - the last thing you need is to go to a center with old equipment that doesn't allow you to save or copy good images. You also want to see if they already have that film there as sometimes they do. Once you determine this you can proceed.
I believe the microfilms can now be ordered online for your state so you will need to log into the Family Search Website
. Click on the tab that says Catalog
. Set the drop down menu to film number and enter the number Biff provided you. Click on the Marano film and scroll down to Nati 1908-1910 Notificazioni, matrimoni, morti 1901-1910 Family History Library INTL Film 1642126 Item 1
. Click on the film number [it's the blue link] and from there follow the instructions for ordering the film using whatever method of payment you want.
You should receive a reference number that payment was successful. Check back a few times during the following weeks to see when the film is sent out [they should provide a reference/tracking number for that too]. Once shipped call the center a day or two later to see when it arrives and book your appointment to view it. If you order the one time short term you need to be able to review it a month before it is sent back to Salt Lake. For 10-12 dollars more you can keep it at your center indefinitely so consider that since you may wish to something else [like Rachele's first husband's death - if he died.]
Hope this is clear..let me know if it's not.