jbod - i'm not even going to approach the argument since it wouldn't help the topic of this thread, but i'd like to point out that maybe you should TRY the sport before you dish on it.
as for snowboarding gear. there's not a definite guide since it depends on what your style and personal preference of riding will be. learn to differentiate boards and their traits, and then try them out to see what you'll like. since you're new you'll probably be doing a lot more freeriding than freestyling, so you won't want a very short board. you may want to consider a directional board that will let you just go down the mountain.
short boards are easier to manuever, long boards are more stable free-riding and will provide a better ride down the mountain. you'd take a short board over a longer one for busting tricks on the halfpipe, etc. the sidecut will also determine manueverbility vs. stable ride. that's the angle of the curve that cuts into the side of your board, a really shallow one will let you bust a much tighter turn, a shallow one will be better going down a large flat area.
as for renting, the major plus i think is that you get to try out different sizes, and get to abuse the f out of them. you don't get to rent too many boards that are really good since they either rent out crappier boards and don't carry the top brands, or won't have any of the top models. also it's a _major_ hassle. it may be worth it to consider a bargain board after trying out what size you feel comfortable with.
anyone that know what they're talking about will tell you boots are the ultimate concern and should be bought in consideration before anything else. you could have a $4000 snowboard and crap boots and will get to know the couch in that lodge _very_ intimately. if you're gonna skimp for a budget, get the best boots you can afford, and skimp on the board itself. my personal reccommendation here if you can afford them is the salomon dialogues, i just got the new 2002 models and they're the most comfortable and supportive boots i've ever used. they have autofit foam that conforms to your feet, incredible support and a unique lacing system that makes them infinitely easier to tighten than any other snowboard boots.
i ride a burton motion 152, burton custom bindings, and salomon dialogues. good luck, and have an awesome seaon