I've been skating for 20+ years, worked at a skate shop, and was a sponsored amateur for awhile. If you are looking to get a board to start out on, there are basically three different "levels" you can get.
First, is the ghetto stuff. I would avoid these at ALL costs. Yes, you can learn some basics on them, but the cheap quality will greatly diminish your ability to have much fun with it. Moreover, it will fall apart quickly. As for these set-ups, you can usually tell how cheap they are just by looking at them. They are often sold in chain-type sporting good stores, so I would avoid theses kinda of stores. If you can, go to a real skate shop.
Second, is the "blank" set-ups. These are a great place to start. Basically, you are getting a quality deck but are not paying for some pro's name to be on the deck or wheels. These can run about $80 to $120 for a complete set up. As a subset of this, companies will often make a "team deck" or something not directly linked with a pro's name. Hence, they are bit cheaper.
Last, is the "pro level" set-up. Here, you are paying for a pro/brand name and are not really go stepping up (if at all) in quality. Expect to pay anywhere from $100 to $150 for a complete set up.
If you have one near by, go support your local skate shop. They usually don't make much money, so they could use the business. When picking out a deck, just stand on a bunch until you find something that "feels" right. Some people like wide boards, some like shorter, etc. There is really "no correct way" to pick out a deck. It's just what you like.
Also, if you do not have skate shoes, get some. Skating is very hard on shoes, and will shred "normal" shoes very quickly. Also, the tread on skate shoes is designed to "grip" a lot more than normal sneakers. I would actually advise you to get skate shoes before you get a deck. That way when you stand on decks at the skate shop, you really know what they are going to "feel" like.
Anything else, feel free to ask.
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