It all depends on your comfort level! (and the temperment of your bees). I have worked bees without any gear at all. I do not recommend this but some people do it. Starting out, you will probably feel like you need an entire suit. Suits are great, especially if you work bees all the time, and getting a ventilated one is well worth it. However, chances are good you will not be in your bee suit 6-8 hours a day. Chances are also good, as you gain experience as a beekeeper you will begin shedding a lot of your protective equipment!
The first time I worked a hive of bees; I had on at least 3 pairs of pants, 5 shirts, and arm length gloves. In the Texas heat that can get pretty miserable. I didn't care though, I was too excited about working the hive to notice. As the novelty wore off and I realized bees usually just mind their business, I shed most of the gear. Within a year I was working bees without any gear at all!
A veil, pair of gloves, white button up shirt, loose jeans, and boots are more than enough, and the most economical choices. Another great option is a beekeeping Jacket. these are not as expensive as a full suit, but provide that extra level of comfort. When choosing your gloves, get ones that come past the elbows, if you do not get a suit with elastic bands, otherwise you will probably end up getting stung in the wrists.
Other Necessary Gear
Hive tool- This is an absolute must. It is used to pry open hives, lids and lift frames. I like the basic hives tool. It looks similar to a painting crowbar.
Smoker- The smoker is another absolutely necessary piece of equipment. It calms the bees and covers up any alarm pheromones that the hive releases. I recommend buying your smoker from Dadant.