If your iPhone is stuck or frozen on the apple logo and won`t restore properly or if it can`t seem to get out of recovery mode after a reboot,
you can first try upgrading your firmware to make sure you have the latest bug fixes.
log into you iTunes account and connect your phone through the USB on your computer.
Then hold down Home and Power for 10 seconds,
then let go of the power button while STILL holding down the home for yet another 10 secs.
You will then go into recovery mode,
and you should click restore in ITunes.
It may not work the first attempt,
but don`t give up,
it will work.