Hi
Welcome back to the forum
I don't think that there is a "book" as such relating to the Fiat Assist in itself, maybe a card with the contact details when help is needed but you should have a Ducato owners manual, a Warranty/Service booklet & a manual for the Sound system, Maybe an operational manual for the AMT if it is fitted with the robotised transmission
Most importantly you should have a second set of keys, a card with the Sound system 4 digit
unlock code along with its serial number, & most importantly a
"credit card" type card with the Electronic & Mechanical code for the Vehicle Keys & Remote
If you don't have these last items for your particular vehicle I wouldn't leave the dealer until I had then in my hand.
Try here for PDF versions of the relevant operating manuals if you can't get the hard copies from the dealer (why not
) -
http://aftersales.fiat.com/elum/SelectModel.aspx?markID=5&languageID=2
There are also X250 owners/operational manuals for download in Ducato downloads section on the Fiat Forum (link at top of Ducato Index page).
Again if nothing else you must get the
card with the electonic & mechanical codes for the keys if in the future a new key or remote is needed & the
unlock code/serial number for the sound system otherwise if you have a flat or a disconnected battery for some reason you won't be able to unlock the radio.
Hope that helps