ST. HELENA. First-time travelers to Napa Valley would be remiss if they didn't visit the CIA's California campus. A word to the wise, though: This isn't the "Mission Impossible" sort of CIA. Far from it, as folks attending the institute's cooking demonstrations would attest. For a real treat, make reservations at Wine Spectator Restaurant, whose terraced gardens, impressive wine list, and superb Californian cuisine make for unforgettable dining.