I'll echo the replies above -- to understand what kind of gear will work best for you, you need experience. I just finished buying my first set of gear piece by piece and I was certified back in May 2000. You can get a lot of good advice from your local shop, on-line and from scuba publications, but it's in-water use that is usually the best test for the kind of gear you want. Also -- talk to other divers in your area about the gear they've chosen and why. By renting gear for the first 15-20 dives or so, you'll be exposed to different types of gear and configurations -- do you like swiveled first stages? weight belt, weight integrated BC or both? Back inflation BC or jacket-style? Will you be diving locally in cold water or only during warm water dive trips? Wrist mounted gauges or console? Computer or analog gauges or both? etc., etc., etc. All of these will have an impact on the types of equipment you buy. If you buy now, you'll end up with whatever your instructor or local dive shop recommends. While most gear sold today is decent quality, if you are going to drop $1,500-$2,000 on a new set of gear, it's obviously better to get what's best for YOU and the types of diving you will be doing that what the LDS has in stock.....
I am glad I took my time -- I feel that most of the gear I have now will keep me happy for at least the forseeable future. Diving is expensive enough without having to "re-buy" equipment every few years.
Good luck!