To JB or not to JB? JB for a dummy

Hi, I am new to the iPad. Reading this forum I had been learning a lot, but also new doubts appeared. For now, my main conflict is to JB or not. I know that this question is not only mine, so I want you to help me to collect information in one thread for reference to the beginners in the iPad world who are facing this decision.

What is Jail Break?
How do I JB my Ipad?
Why the version is important?
What is Cidya and how it works
What happen to my apps bought from the store?
Is it possible to reverse the process? How?
Tethered or untethered? Which is the difference?
My main purpose in JB is to use sd cards for extra memory, is it possible with 4.2.1? Does it really work?
Ifiles from app store works with a JB iPad?
Main Advantages
Main Disadvantages
Known problems

Thanks to all!!

http://www.ipadforums.net/ipad-hacki...plained-8.html

http://www.ipadforums.net/ipad-hacki...-benefits.html

The real ifiles only comes from cydia. Ipad has to be jailbroken. U need to do some research buddy. All the info u request is right here in the threads and stickies. The possibilities are endless being jailbroken ;-)

+1 for the endless possibilities.

I just love that my folders close after I chose an app or that safari stays on the tab I'm on and opening new web pages in the background. And then there are the great springboard shortcuts for turning on and off different features of the iPad without the need to go through the settings thingy.

there is no point in not jailbreaking...... if anyone tells you oh well i dont really useit for anythign or its not that cool or anythign of the sort well they jsut really hve no idea what you can really do with it,.... endless possiblities.... and free ones too, and if you do have a prob with that part of it, well let me tell you i dont give a **** what you think in that case

Here is some reading that may be helpful!

http://www.ipadforums.net/ipad-hacki...-benefits.html