Accidental damage is not covered under warranty, so you could take it to any number of places. The repair itself is not trivial though, so you'd want someplace you can trust, and preferable is an official Apple authorized repair facility.
From past posts here and elsewere, it seems if Apple does it, the cost is somewhere around the $300 USD mark and typically takes a couple of days (assuming parts are available - replacement parts are not always readily available as most iPads "repaired" under warranty are actually replaced with factory refurbished units, and the broken item gets sent back to China for refurbishment if possible).
Other online places say the repair can be from $129 to $220-$250 depending on damage. iFixit has a guide to the process - http://www.ifixit.com/Guide/Installing-iPad-2-GSM-LCD/6161/1 and rates it as a "very difficult" repair.
Apple is not going to fix it. They will give you a new or refurb, most likely a refurb. if they have one in stock. You will be paying the out of warrenty charge, starting at $269 and up, depending on model. If they do not have a refurb to give you, then it will become a shipping issue.
If you have your friend go to a non apple repair place, I would expect nothing less than a couple of days, and only that repair place could give you a better estimate.