The non-negotiable stuff: a helmet and a bike. A hard tail is a mountain bike that only has suspension in the front, which will be cheaper and fine for beginners. If you have the cash, a full suspension mountain bike will be more deluxe, but isn't necessary. If you're interesting in road biking, frame weight and components will be what drives up the price. Both Johnson and Fox recommend buying a bike from a store rather than Craigslist, because bikes tend to be overpriced and the fitting you'd get from a bike shop, plus the free tuneups, will make spending extra cash even more worthwhile. If you have a gearhead friend to bring along or to advise you on your purchase, however, online sales are where you can find a screamin' deal.
Technical clothing that isn't cotton will be more comfortable. You don't want anything too baggy—it can catch on your saddle as you sit and stand, so avoid basketball shorts, Johnson says. Padded bike shorts are a lifesaver, especially if you're interested in longer rides. You don't need to wear underwear with padded shorts though—the seams can create hot spots and won't do you any favors. Most road biking apparel will be more tight-fitting, but jerseys will come with pockets on the back where you can stash tools and food. Plan on bringing extra layers, especially if you'll be out in the woods.
Something flat with a sturdy sole will be ideal, especially for mountain biking. If you're more confident in your cycling abilities you can opt for clip in shoes, which have cleats on the bottom that click in and out of the pedals.
A hydration pack is great for mountain biking — get a drink without having to fumble with a bottle while maneuvering uneven terrain, plus throw in some snacks and extra layers. A multi-tool, pump or CO2 canister and a spare tube are must-haves, so you can avoid the long walk back when you get a flat.
Water bottles will serve you well on the road, but it can be helpful to have two water bottle holders so you can plan on drinking 16-20 ounces per hour. If you're planning on being out for more than an hour, you'll want food; simple carbs will hold off the bonking, which happens when you run out of energy and hate your life and question every decision you have ever made, according to Fox. Gels and energy shots are made for athletes on the move, but something like a chocolate-and-nuts bar will get the job done, too.