If you're a long time fan of Sony gaming devices, you're probably already familiar with the PlayStation Store. The good news for you is it's not much different on the PS Vita. If the PS Vita is your first Sony handheld, though, you might want a few pointers.
The PlayStation Store is part of the larger PlayStation Network, and though you can browse it without signing up, if you want to be able to download anything, you'll need to get a PlayStation Network (PSN) account. If you need help setting up a PSN account, you can follow these instructions (they aren't PS-Vita-specific, but they're pretty much the same).
Once you have an account, you'll be able to purchase games, video, and other content, and download freebies like demos and wallpapers. Even if you only buy games at retail shops it can be worth getting an account for the demos. And if you plan to play multiplayer games online, you'll need a PSN account for that, too. This article goes into more detail about downloadable games.
Accessing the PlayStation Store
Whether you just want to browse or you're ready to shop, you first need to get into the PlayStation Store. On the PS Vita, just tap the Store icon to bring up its LiveArea screen. If you're already signed into the PlayStation Network, there will be "live items" related to current featured games on the PSN. Tap the items to get more information.
To get into the Store proper, tap the "gate" (that's the rectangle in the top middle that has a "start" button on it) to launch the Store. You'll also see icons at the top for things like inputting coupon codes (it looks like a pencil and some numbers), refreshing the screen, and more.
You can also access the Store via a PS3 and transfer content to your PS Vita later.
Keep in mind that some content is region-specific and you can only access the region that your PS Vita is registered in. So if you're in the US or Canada, you'll only be able to get to the North American Store.
Navigating the PlayStation Store
At the top of the screen, you can switch between the Game and the Video stores, or use the search box if there's something specific you're looking for. Below that, you'll see ads for featured content--tap them to get more information. Finally, there's a list of content (showing icon, title, price, and rating) with tabs for sorting by Recommended, New, Top Downloads, and Category. Tap these headings to browse, and scroll down the resulting lists. When you see a title that interests you, tap on it to get more information.
How To get Content
When you've found something you want, tap on it to bring up the detailed information screen. There, depending on the type of content, you'll see buttons that say "Buy Now," "Rent Now," "Get Now" or "Download" (that last one will only show up once you've purchased the item). Tap the appropriate button to start the process, and remember you'll need to have a memory card in your PS Vita with sufficient memory to contain the download.
Once you tap the "Buy Now" or other button, another screen will load, showing the details of your purchase. Look it over, and then tap "Confirm Purchase" (or "Cancel" if you've changed your mind). Once the purchase in completed, the download will start immediately. You can also re-download items again by going to your list of purchased items (in the "Options" menu) and selecting "Download."
The PlayStation Store uses a virtual wallet for purchases, so you'll need to have money in your wallet before you can buy anything (you don't need this for free items, or course). You can add money to your wallet by purchasing a PSN card from a game shop and then input the code into the coupon area, or you can add finds from a credit card. If there's no money in your wallet when you attempt to make a purchase, you'll be prompted to add funds. Follow the instructions to set up your wallet.