The advice so far is pretty good when taken as a whole. However, I will consolidate it a bit-
Snowshoes-if you can walk, you can snowshoe, it's that simple. For your weight, get the biggest shoes you can find. The old school wooden shoes are great for Northern Canada where the ground is flat and the snow deep and fluffy. Otherwise, just get a big pair of Atlas or similar shoes. I'd stay away from MSR's-they are probably too small for you without the tails and may be awkward with them. Get poles, as already mentioned. Cheap ski poles will work fine. I use my trekking poles with snow baskets on them.
Rent, then buy. You may find you don't like snowshoeing, who knows. Used snowshoes are fairly common on eBay or Craigslist. As long as they aren't beat up, there isn't a lot to go wrong with them.
Skis- higher learning curve, more expensive. You can snowshoe in almost any boot. My backcountry ski boots (Garmont Excursions) retail for about $350 just for the boots. Skis and bindings about the same. My gear is for backcountry skiing, but in fluffy stuff, they aren't wide enough.
XC skiing on skinny skis on packed trails is a whole other deal which others can comment on. That's not my setup.
Here is an online magazine for snowshoeing. I've linked to their beginner's section. http://www.snowshoemagazine.com/first.cfm
The link is also in the drop-down menu on the left that you will see once you are past the home page with the big picture on it.