One of the worst things about syncing an iOS device was that it had to be plugged in to your computer by USB. Not anymore. Now, if your computer and iOS device are both connected to the same Wi-Fi network, you can sync all your applications, books, movies, tv shows, music, podcast, audiobooks, ringtones and photos without plugging any wires in.
How to Sync over Wi-Fi
In order to enable wireless syncing you have to plug your iOS device to your computer by USB one last time. Plug in your device and go to the source list in iTunes, then scroll down to the summary pane. Your iOS device can’t sync with iTunes when iTunes isn’t running, so you’ll need to check two boxes in the options section. Check both, Open iTunes when this iPad (or iPhone/iPod) is connected, and Sync with this iPad (or iPhone/iPod) Over Wi-Fi. Once both are checked, simply press the sync button to save your changes.
There are two ways to get your device to sync now, one is by going to the Settings app on your device and tapping General -> iTunes Wi-Fi Sync -> Sync Now, which will simply start syncing right away. The other way is to have it automatically sync whenever you plug your device in to charge. For instance, I plug my iPhone and iPad in on my nightstand when I go to bed, when I do that it automatically sync with iTunes. No need to even think about it. It’s pretty much a simple setup that you only have to do once for each of your devices and then just forget about it.
Once and iOS device is connected to iTunes it can be accessed from the button on the upper right hand side of iTunes.
If you have more than one device connected, they will all show up in the little devices pane. Select the one you’d like to go to and you can select or de-select media to sync.