Get an introduction to digital cameras in this free lesson, which covers the basics and dives in to more advanced features as well.
Most digital cameras store photos on a separate memory card, such as a Secure Digital, SDHC, microSD, or CompactFlash card. These cards usually have several gigabytes of storage space, and the exact number of photos they can hold will vary depending on the resolution and file format of the photos. You may need to purchase a memory card separately, and it's important to choose a card that is compatible with your camera. You can find this information in your camera's manual, on the outside of the box, or online.
Generally, you'll want to use the memory card as temporary storage until you transfer your photos to your computer. You can then delete the photos from the memory card so you'll have plenty of space for your next photo shoot.
Generally, cameras use rechargeable lithium-ion battery packs, although some can use AA batteries. The battery pack is usually included with your camera, but you may want to buy an extra one in case the battery runs out while you're shooting. Make sure to buy a battery pack that is designed to work with your camera.
Your camera will also come with a charger you can use with your battery. It's a good idea to recharge the battery overnight so you'll be ready to take photos the next day.