As this is your first trip to Europe, my first suggestion would be to read Europe Through The Back Door. That will provide you with a LOT of information on how to travel efficiently in Europe (including Itinerary planning).
Your trip is VERY short so careful planning will be essential. Keep in mind that you'll lose the first day in flight times and time zone changes and the last day will mostly be spent traveling. Visiting 6 locations in 8 days (as suggested in the first post) is not really practical IMHO. Is there any way you could get a few extra days (it would sure help!)?
To visit the destinations that both you and your Wife want, you might consider something along these lines:
Day 1: Flight to Paris
Day 2: Arrive Paris / CDG - light touring if you have the energy
Day 3 & 4: Paris - touring (plan carefully so that you can fit as many sights as possible - prioritize!).
Day 5: Budget flight to Milan / MXP (EasyJet from CDG suggested - more flights available incl. early flights - be sure to PACK LIGHT or you'll pay overweight baggage charges) - Shuttle to Milano Centrale, buy tickets to Cinque Terre via La Spezia - light touring when you arrive.
Day 6: Cinque Terre (check Italy Guidebook to determine which town to stay in)
Day 7: Train to Rome - use direct train from La Spezia - about 4 hours, no changes, but reservations compulsory - arrive Roma Termini (be sure to wear a Money Belt!).
Day 8 & 9: Tour Rome - again plan carefully!
Day 10: Leonardo Express to Roma / FCO for flight home.
This only provides about 2-days for touring both Paris & Rome, but if you plan your touring well, you should be able to cover lots of sights while still "pacing yourselves" to some extent.
Use the Guidebooks for lodgings in each place, or ask for suggestions here.
I tried to cover all the places you mentioned. Once you've decided, the group can provide more specifics.