Browsing decks online is best when you're looking the actual brand's website, rather than a retailer that carries a lot of different brands. The company site usually gives you a taste of what the brand is all about, in addition to what their decks look like. A lot of brands have their own skateboarding teams. If you happen to like a rider on a team, that can give you a strong connection to a brand (and they'll probably have a deck with your favorite rider's name on it). You also might be drawn to a particular philosophy of the brand or a specific design or construction feature used on their decks. For example, some companies are known for killer graphics, and some play around with different materials to give their decks unique performance characteristics.
Here's some general guidelines to get you started: Narrower decks are lighter and easier to flip, but you’ll sacrifice some stability. Wider boards are more stable but are heavier and slightly less ideal for some tricks. Skaters who like flip tricks, manuals, ledges, and flat bars usually prefer boards on the narrower side of the spectrum (7.75 – 8.25 inches). Those who skate big bowls, hand rails, or like to jump down large gaps at high speeds are usually more comfortable with a larger board (8.25 – 9.0 inches).
Next, you’ll need to look at the deck material. Decks are typically wooden or plastic, but they may also be made of materials like carbon and fiberglass. Plastic boards, like the pennyboard, are more affordable, and still very durable, but many adult riders find that they can look a bit like a child’s toy rather than a “real” skateboard. Wood is the most popular choice for most skateboards, although if you want to invest in the pricier fiberglass or carbon options, you’ll get a very good quality deck for your money.
Without good grip tape, skaters have a tough time staying on top of their board. The main complaints about poor grip tape tend to be that it was never very grippy or lost its grip really quickly. Once again, we recommend trusting in name brands with years of experience supporting skateboarders. Unfortunately, if you are buying a pre-made complete skateboard, you probably won't have access to the brand name of the grip.