To sync an iPhone to your computer, connect the iPhone to your computer via the USB cable that came with the iPhone, and select your iPhone from the iTunes source list. Type a name into the text box next to Name, tick the two check boxes, and then click Done.
If you have already set up and named your iPhone, skip the Set Up Your iPhone page. Click the Summary tab located near the top section of the iTunes window. If the Summary tab does not appear on the iTunes window, select the iPhone in the source list located on the left-hand side of the window. On the Summary tab, choose one of the provided options for synchronizing your iPhone to your computer.
If you did not tick the check box next to Open iTunes When This Phone Is Connected, click the Sync button located at the bottom-right corner of the iTunes window. If you changed your settings on iTunes since the last time you synchronized the iPhone to the computer, click the Apply button. This process transfers all purchased media and other important data from your iPhone to your computer and creates an updated backup of your iPhone every time you want to restore the iPhone.