Ray, one of the worst oversights in booking Venice is an early morning trip to the airport from the main part of the city. To use reasonable transportation (buses, Alilaguna, etc.) you just can't have a flight depart earlier than 8:00am. Even though transportation services start as early as 4:00am, it's a struggle to get there in time for the proper check-in.
What traveler's are forced to do is hire a water taxi for high-speed water transport to the airport. It's currently running 100E-115E ($155-$170) to hire a water taxi.
However, I would strongly suggest staying near the airport. There are a few hotels there. I would suggest the Marriott Courtyard which is .8km from the airport. 132E/night. Not sure about shuttle. You might also look into the Titian Inn Hotel and Residence. It's also nearby the airport and, they have a shuttle. http://titianinn.hotelinvenice.com/overview.html?source=-titian+inn+hotel+venice