At present, there's only one boat on that run. There's supposed to be a second one towards the end of July. A reservation is strongly recommended and you can make it through the Ferry System's website, www.wsdot.wa.gov/ferries
We haven't been over to the peninsula for a while, so I'm a bit out of date on campgrounds. There's one just west of Port Townsend called Salt Creek County Park. A photograph of it is used as the header on the iRV2.com newsgroup. It looks across the Strait towards Victoria. I believe there's another nice one at Crescent Lake.