Book hotels well in advance. Hotel reservations, always advisable, are generally necessary from late spring through October and on many weekends. To be on the safe side, book smaller hotels and inns at least a month ahead. Many of these have two-night minimums on weekends, three nights if Monday is a holiday.
Call restaurants ahead. Reserving a table, or asking your hotel to reserve one for you, can save you time waiting at the door.
Reserve at wineries, too. If you're keen to taste at a specific winery, double-check hours and tour times and, if possible, make a reservation. You can often make reservations for tastings, tours, seminars, and other events. Keep in mind that visits to many wineries are by appointment only, either because their permits require it or because they want to control the flow of visitors to provide a better experience.