Hi. I may be able to help you, but I will need more information. Specifically, which device are you trying to pair to your iPhone? I assume you're talking about Bluetooth, right? You can use Bluetooth devices with your iPhone, including headsets, car kits, stereo headphones, or an Apple Wireless Keyboard.
To specifically answer your question, I would need more information about what you are trying to pair with your phone. Note that the documentation that came with your device (headset, car kit, etc) should contain instructions. Is it a Plantronics that you're trying to pair by any chance?
Also, from the title of your post, it appears that you're trying find free manuals for your iPhone. You can access the iPhone Manual from this site: http://support.apple.com/manuals/
If that link doesn't work for you, just go to www.apple.com, click on the Support tab located in the bar at the top of the screen, then scroll all the way to the bottom of the page and look for Manuals under the Resources column in the rectangular "Support" box at the bottom. From the new page that opens up, select "iPhone User Guide -- For iOS 7.1 software." You can download the manual or simply view it. It is very long! Bluetooth Devices are located in Chapter 3: Basics, page 35. BUT, the manual doesn't really tell you anymore than what I've listed below.
Here are some basics, if that is all you're needing:
Turn Bluetooth on.
Go to Settings > Bluetooth.
Connect to a Bluetooth device.
Tap the device in the Devices list, then follow the onscreen instructions to connect to it. See the documentation that came with the device for information about Bluetooth pairing. (For information about using an Apple Wireless Keyboard, there are different instructions.)
iPhone must be within about 30 feet (10 meters) of the Bluetooth device.
More basic instructions are here:
Return audio output to iPhone.
Turn off or unpair the device, turn off Bluetooth in Settings > Bluetooth, or use AirPlay to switch audio output to iPhone. See AirPlay on page 34. Audio output returns to iPhone whenever the Bluetooth device is out of range.
Bypass your Bluetooth device.
To use the iPhone receiver or speaker for phone calls:
Answer a call by tapping the iPhone screen.
During a call, tap Audio and choose iPhone or Speaker Phone.
Turn off the Bluetooth device, unpair it, or move out of range.
Turn off Bluetooth in Settings > Bluetooth.
Unpair a device.
In Settings > Bluetooth, tap next to the device, then tap "Forget this Device." If you don't see the Devices list, make sure Bluetooth is on.