Q: Best protection software to buy for ipad 3

What exactly do you mean by "protection software"? Protection from what? If you mean malware, there isn't any thing and nothing is needed as long as the device is not jailbroken.

Currently there's no known virus affecting iPad as long as you don't Jailbreak your iPad.

http://support.apple.com/kb/HT3743

A jailbreak is a 3rd-party modified version of iOS. It is NOT recommended, as it voids the device's warranty, exposes it to malware, and much more.

If you don't know what it is then you have not done it.   Jailbreaking is basically hacking the iPad to make it do things it was not designed to do and install software from untrusted sources, which opens it up to a lot of nasty possibilities.

Jealbreaking is not supported by Apple, and will void the warranty if performed on a device. Its a fairly involved process though, and we are not allowed to talk about it in these forums for that same reason.

You should not need to worry about it, if the iPad has never been out of your reach for extended periods of time.

Note that although the device is fairly immune to most nasties if not jailbroken, the user may not be as resistant….

The miscreants out there are ever so more creative into tricking innocent people into disgorging personal info they can use to get into their wallets, or worse (speaking as someone in a kidnap-prone country where location info is attractive to kidnappers). Safe computing is a lifestyle and a state of mind.

And I will second Courcoul's advice. Most times, the weakest link in security is the user himself.