We went to Petra, the old Nabataean Capital, last July and we were fascinated. Sometimes you go with high expectations to a place and when you're finally there...it's disappointing. But not here. Don't be afraid, your expectations will be exceeded.
Of course everyone, or almost everyone, knows what at the end of the Siq (canyon): the Treasury. Yes, I saw "Indiana Jones and the Last Crusade" too. But anyhow, it's a breathtaking view.
But there's a lot of other things to see: the Roman Theater, the Kings Tombs, the amazing color of the stones etc. So be sure that you stay in Petra for at least one day.
If you are not too lazy you should take the walk up to the High Sacrifice Place. Take the long way up (1,5 h) and the short way down (30 minutes). Believe me, it's easier this way. You will be rewarded with a breathtaking view over Petra. Take enough water with you for this hike!
There aren't a lot of possibilities to buy lunch. The best thing you can do is bring your own food with you and have a picnic in these amazing surroundings. But there are a few places where you can buy a cold soft drink or have a refreshing, hot tea (no kidding, give it a try!). Make sure, that you drink enough. The summers in Jordan are very hot (100°F/40°C and more). And you will walk quite a few miles in Petra. So don't wear sandals or even flip flops. And make sure that you bring a sunglass, a hat and suntan lotion with you. Long trousers and a blouse with long sleeves are also recommended (the Beduins are Muslims and it will protect you against sunburn).
Although it's very hot in the summer I would go to Petra any time again. The summer isn't the peak season in Jordan, so there aren't that much tourists as in the fall (peak season). And the prices for the souvenirs are better, too! Don't forget to haggle with the Beduins (except at the shop with the sandbottles, the prices here are fixed). So if you don't bother about the heat, go to Jordan in the summer.

One of the most wonderful treasures in the world, breath-taking scenery, magical and sacred. Hiding in Wadi Musa in the vast Jordanian desert, I loved it.

My family (grandparents, parents and 2 children (8 and 11) ) visited Petra from Eilat, Israel. We were picked up at 7:30am from our hotel and brought to the Jordan/Israel border. We returned to the hotel around 7:00pm.
This was one of the highlights of our trip. Everyone - children included - were awe-struck by the beauty of Petra. We traveled by foot through the Sic and continued by foot to the restaurant area by the museum. On the way back, however, we rode the donkeys (about $4 US per donkey) back to the ampitheater and then we rode 2 chariots ($30 per chariot) back through the Sic to the entry.
Pictures do not do this city any justice. This was an experience that we will not forget!

We took a trip to Petra from Sharm el Sheikh in March 07 booked with Thomson. Don't get me started on the price - there were considerably cheaper options to be had, as I found out after the event - but overall we had an excellent bedouin guide who went to great lengths to explain the history of this amazing place, who, apparently works only for Thomson.(?)

It was a very long day, picked up at 5.30 am, returning to hotel at 9pm but everything ran very smoothly and we had a very comfortable time travelling. Lunch was at the Movenpick hotel - excellent selection.

It is a very long walk into the city, make sure you go prepared and take walking boots/trainers. There are beautiful arab horses that you can pay to ride instead of making the trek on foot but we were advised not to as they were a bit 'frisky'. From what we saw, I would say they wouldn't be a problem for experienced riders.

There is opportunity to buy water before you enter the city - we only had Egyptian LE but they took that (fyi, 1JD = 1GBP)

I don't want to give too much away as you will want to see for yourself! Definitely recommend this trip, wish we had gone for longer and spent more time visiting the region.