I used to run Crank Brothers Mallet clipless pedals, and if I had to go back to clipless pedals I would do the same, with some of the new Five Ten SPD-compatable shoes, since they give you enough grip on the pedal to ride through a section not clipped in, if you feel the need to. I do prefer to ride flats (PointOne Racing Podium pedals) with a set of non-SPD FiveTen shoes (I've used the original Sam Hill edition Impacts and am on a set of Freeriders now, really comfy, looks like a skate shoe and they're not that bad to drive in, either), and as such, I would suggest picking up a set of the SPD-compatable FiveTens, and a decent set of thin (~17mm or thinner) flat pedals, and ride for a while with that setup, then get a set of either Candys or Acids (my preference, has enough platform to let you ride not-clipped in through a section or if you have to unclip you can make a few pedal strokes before clipping in, if necessary), cut the little plug out of the sole of the shoe to reveal the SPD mounting holes, bolt your cleats up, and have fun. I made the mistake of going to SPD-based pedals too soon, and if you ride aggressively, you can certainly learn some bad habits, such as of pulling up on the pedals to get the rear end off the ground when trying to bunnyhop, which definitely does not translate well to riding flats, but if you learn to bunnyhop a decent height with flats, then move over to clipless, you will be a lot better off imho
EDIT: if you're just a recreational rider hitting the trails every once in a while, I would stick with flats and go the Five Ten/decent pedal route. look for something with screw-in traction pins, either long set screws, or if you can find them for a decent price, a set that have actual screws that thread in from the opposite side of the pedal. for reviews, just hop on mtbr.com and go to their forums, to the All Mountain, Downhill/Freeride/Dirt Jump sections, lurk around a bit, and see what most people are running for flats, and go with those. as far as shoes go, Five Tens are the ones to have, as the rubber they use will stick to the pedals like a set of brand new R-Comps on swept-off pavement. the ones designed to be SPD-compatable have a stiffer sole and thus will transfer power better, but they won't be as comfy to walk around in. the non-SPD versions are more flexible so they are more comfortable, especially in hike-a-bike situations, but they won't transfer power as well, due to the more flexible sole