Verified answer

Yes you do. Take backup of all your data before doing it and you can put it all right back onto the iPad.

Nope! One time I jailbroke my iPod 3 and all my data was still there:) but I don't know if you can jailbreak iPads...

No, if you go to jailbreakme.com to jailbreak it, you won't lose anything. It just adds cydia.