Most wood used in cabinetry is usually oak, maple, cherry, and some walnut. Poplar is sometimes used, but it is usually painted or veneered. Some exotic woods are sometimes used, but they're not not very common in production cabinets. Oak is an open grained wood, while the others are closed grain. That means that oak is usually somewhat rougher to the touch. Not that it's not smooth, but you can "feel" the grain when you run a finger over it, unless they (the builders) used a grain filler during the finishing process (not very likely).
You should be able to go to a big box store like Home Depot or Lowes and get a small piece of each type. If the big box stores don't have any, try someplace like Woodcraft or Rockler. You don't need much, just enough to try some test stains or finishes.
2007 Travel Supreme Envoy 40DS04