Bullet points, just things labelled 1, 2, 3 ,4

My device is charged

Look on the left hand grey column of iTunes you will see:

LIBRARY
STORE
DEVICES

Click on DEVICES your device should be listed there (iPad, etc)

In the middle of the screen you should see your device

There should see Version with an option "check for update" or "restore"

You can choose to select update or restore, a warning prompt will come "Are you sure you want to restore (device etc) to it's factory settings, all your media and other data will be erased. (if you choose to restore)

There will be a prompt and your item will turn on and off, do not unplug it, just leave it during the restore process it can take a while so ensure your laptop is plugged in and not on a low battery

Just a tip as well ensure you keep your devices out heat as my wifi got fried on my iPhone when it was in my bag just walking around they seem fickle

Before restore check iTunes to look at how your songs etc are arranged in the order you want