The good news is that, for an overnight trip, you probably could pack four or five Snickers bars, a few tablespoons of instant coffee, a book of matches, a wool sweater, and a large garbage sack and get by just fine. I mean, you could stand on your head for the 36 hours the trip will last, and come out of the experience just fine.
In any event, what you take will depend a great deal on how far you intend to bicycle, your access to food along the route, and the weather forecast. In terms of clothing, simply think of what’s comfortable for you on the bike, and what’s comfortable in camp. I like baggy-style shorts when touring, as they look less dorky than tight shorts and have handy pockets. Bright jerseys are appropriate, dorky or not, for safety device as they make you more visible to traffic. For camp, I’d likely take some light nylon trousers, maybe a pair of lightweight long underwear tops and bottoms (handy if cool when cycling, too), a light Polartec jacket and maybe a light rain jacket.
I wouldn’t pack a tent; take a tarp and some strong cord and rig something up if necessary. For one night a thin foam pad is fine-Cascade Designs’ Z-Rest ($35) is perfect, and weighs only one pound. If you take a stove, make it a light, compact one such as the MSR Pocket Rocket ($48), and pack one fuel canister. I can’t answer the sleeping bag question-it depends entirely on how cold you think it will be. I’ll assume summer in New England, so a bag rated to 40 degrees ought to be fine.
In terms of lugging all this stuff, you’ll need to purchase a luggage rack for the backs of the bikes and a pair of panniers. Good ones need not cost a lot; try Performance’s Transit Pro, a decent mid-sized pannier for $80/pair. Pack the heaviest stuff low in the bags, with lighter stuff and things you’re apt to need during the day (sweater, lunch, first-aid kit) near the top. Strap your sleeping bag and tarp to the top of the rack with bungee cords; those also can be used to tie down loose items such as camp shoes or a big water bottle.
Otherwise, just have fun. I think bicycle touring is one of the most entertaining diversions possible. It combines the workout and sense of independence of a good backpacking trip, with the ability to stop on occasion and buy a half-pint of cold chocolate milk!