I ride both, after a bad crash, I lose my mojo and blame the SPDs or Eggbeaters, then go to flats. It's a never ending cycle. Start with flats, and after getting comfortable riding technical trails, give clipless a try. For clipless, I really like having them on seated climbs and bumpy downhill runs. Also get the right pedals and shoes for flats, 5010 sneaks with any pinned pedal like RF Chesters are really sticky.
Hmm, you're in BC? have you considered a fat bike or studded tires for your area? Many of our trails are not rideable after a good snow, that is till after snowmobiles, XC skiers or fatbikes get to them first. And then there's the freeze and thaw which often makes sections like ice rinks. And I'd ditch clipless if riding on ice.