Apple's design philosophy is to keep things simple, and as you can see in this diagram of the iPad, there are only a few buttons and features on the exterior. But as you might expect, each one of these features plays an important role in using your iPad, including a basic navigational tool and the ability to put your iPad to sleep and wake it up.
The iPad Home Button
The iPad's Home Button is used to close out of an app and return to the home screen, making it easily the most important button on the iPad. You can also use the home button to wake the iPad up when you want to start using it.
There are also a few other cool uses for the home button. Double-clicking the home button will bring up the task bar, which can be used to close down apps that are still running in the background. And triple-clicking the home button will zoom in the screen, which is helpful for those with not-so-perfect eyesight.
Another neat trick is using the home button to quickly go to the spotlight search screen. Normally accessed by swiping your finger from left to right while on the home screen, the spotlight search can also be reached by clicking the home button a single time while on the home screen. Spotlight search is used to search through your iPad's content, including contacts, movies, music, apps and even a quick link to search the web. How to Use Spotlight Search to Launch an App
The Sleep/Wake Button
The Sleep/Wake Button does just what its name implies: it puts the iPad to sleep and wakes it back up again. This is great if you want to suspend the iPad automatically, but you don't have to worry about doing it every time you stop using the iPad. If the iPad remains inactive, it will put itself to sleep.
While the Sleep/Wake Button is sometimes referred to as the On/Off Button, clicking it will not turn the iPad off. Powering down the iPad requires you to hold this button down for several seconds and then confirm your intention by swiping a confirmation slider on the iPad's screen. How to Reboot Your iPad
Volume Buttons and Mute Switch
The volume buttons are located on the upper right side of the iPad. The mute button will immediately eliminate all sound coming from the iPad. The functionality of this button can be changed in the settings to lock the orientation of the iPad, which is great if you find yourself holding the iPad at a peculiar angle that causes it to rotate the screen when you don't want it to rotate.
Holding down the volume decrease button will also turn the volume completely off, which is a great trick when you change the mute button to lock the orientation rather than mute the sound.
30-Pin Connector/Lightning Connector
As mentioned previously, newer iPads come with a Lightning connector while older models have a 30-pin connector. The main difference between the two is the size of the adapter that plugs into the iPad. This connector is used to plug the iPad into your PC. You can also use the AC adapter that comes with the iPad to plug it into a wall outlet, which is the best way to charge your iPad. The 30-pin connector is also used to connect various accessories to the iPad, such as Apple's Digital AV Adapter, which can be used to connect your iPad to your TV.
Note: You don't need to ever plug your iPad into your PC. The iPad can be setup without a PC and you can download apps, music, movies and books to it without every plugging it into a PC. You can even backup the iPad to the Internet using Apple's cloud services.
The headphone jack is a 3.5 mm input that will accept sound signals as well as outputting sound, so it can be used to hook up a microphone or a headset with a microphone. Among the other uses for it include musical uses, such as using iRig to hook a guitar into the iPad.
The iPad has two cameras: a back-facing camera, which is used for taking pictures and video, and a front-facing camera, which is used for video conferencing. The FaceTime app can be used to create a video conference with any friends or family who either have an iPad (version 2 and above) or an iPhone. How to Use FaceTime on the iPad