I must say that your time allocations look odd to me. Only one day for
Venice, including travel time? And the same for Florence? I've want to
go to Turin for some time, and I've read nothing but good things about
it, but in this case I'd drop it to allow a bit more time for Venice
and Florence. Rome needs more time as well.
Another welcome to the forums, Ms Girlandabear -
I will agree: by the time you get to Venice and Florence you barely have time to get settled before having to pack up and leave again. Neither of them make sense for just part of a day, IMHO. 2.5 days is not enough to even start to scratch the surface of Rome: I'd scrap Pompeii and save it for a trip when you can cover Naples and points further south.
Paris> Venice>Turin> Florence>Bologna route is confusing too. Turin, as mentioned earlier, is closer to Paris than Venice, and Bologna is north of Florence. To avoid backtracking it would have made sense to do that one BEFORE Florence if heading south to Perugia and Assisi. But any advice we might give you regarding rerouting/re-allottment of time is probably for naught at this point as I've a feeling you may already have bought tickets and made reservations for your accommodations/car?
The CT is too far to day-trip from Bologna by either train or highway. The only city on your list that it's reasonably done from is Florence and it's even a bit of a stretch from that one.
"Best" guide - assuming you mean a book - is up to personal preference. Being you're on the RS website, the consensus here will roundly be for his Italy book. Other folks like Eyewitness (I do) or even Lonely Planet, depending on age/interests. Best thing to do is to make tracks (!!!) to a bookshop and look them all over before making a choice.