How do I restore the ability to pair

You can try to pair the devices first. If it's already paired but not connecting, you can reset the connection by having your phone "forget" the bluetooth connection. Then pair it again.

Go into the iphone and remove any devices left in the Bluetooth cache.clear cache and forget any device.then start a new search.
i have heard it is sometimes possible to refresh by turning on airplane mode then back into network.this also a good way to restore airplay.

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.

forget the headset
turn bluetooth off
turn the headset device off
reboot phone.
try again

First thing you need to do is to go into your Bluetooth settings and make sure that your phone is set up to pair with a device. Next, make sure that the device your are pairing to your iPhone, is in pairing mode. After both of these steps are complete, the phone should recognize the device and you can complete the pairing process. Hope this helps!

remove other paired devices on your device, may be the device has crossed the limit of phones it can connect.
start pairing fresh on both devices- phone and bluetooth device.,

If you have the headset paired w/ another device, you have to "forget" it on that device and then try to pair w/ the iPad.
I was having the same issue w/ new iPhone 4, but this solved it for me. It is a bit annoying to have to forget and unpair every time you want to switch devices, but oh well.

Remove the device from the computer, and remove the computer from the phone, then start over and try to pair again

To your diappointment the Iphone cannot send photos, songs, or anything like that, yet. What you can try is restoring your Iphone and then see if you can pair it with your device. If that doesn't work, then it just means that the device you are trying to pair with it non-compatible with the Iphone.