Havasu Falls?

Went there a couple of years ago.  My wife, daughter (8), and myself.  We hiked in and out and tent camped the whole time.  I don't know what stage you are in in the planning process, if you have reservations or not, but I would get them ASAP.  You want to start early and you want to wear layers or convertibles (my preference).  For ours we flew into vegas in the morning and drove down in the afternoon.  It was the cheapest flights for us. We got Peach Springs late in the day so we ate, set up camp and went to sleep.  We camped at the Grand Canyon Caverns camp grounds so that we could get a reasonable start on the hour drive into the trailhead.  We woke up about 4 am and packed everything up and got on the road.  The temps are much cooler up top than when you get into the canyon.

We carried a 3 liter water bladder for each of us and drained it by the time we got there.  I also packed a couple of gels just for a little bump and some granola bars.  We ate lunch at the cafe once we got to the village.  It's burgers and EXPENSIVE but you really don't care by the time you get there.

The trail is also shared with pack mules and my number one suggestion is to take a bandana and wear it around your neck for a) soak with water to help you cool down a little and b) pull it up over your mouth when necessary (like passing horses) to cover from the dust.

It takes every bit of 5 hours to go the 10 miles and it MUCH easier in than out.  When you get to the camping sites don't just take the first one you see.  Walk back into the grounds, there are better campsites further back in.  By the time we figured this out everything was already set up.  I would suggest looking for a site that is elevated a little bit, sheltered on a few side by vegetation from the wind.  Sand blows into your tent during the day even when the fly is completely zipped up.

Don't break in a pair of hiking boots on this hike, you'll regret the blisters.  Take water shoes and quick dry clothes cause you'll want to spend time splashing around in the water and the river bed is quite painful on bare feet.  

Mooney falls is now better than Havasu falls IMO, so make sure to go see that.  Also there is a small underground cave behind one of the small water falls at Mooney falls.  It's kind of cool to sit behind the waterfall and look out.

Take a small day pack to carry lunch so you are not tied too much to your site.  It'll allow you to get past Mooney falls and hike down to the colorado if you like.

When you leave, try to leave before sun up, you will be climbing the toughest part of the trail during the hottest part of the day if you don't.

you'll want pictures.  Mine are too big to download but I'll give it a shot anyway.  But you'll want to take pictures of everything.

Otherwise enjoy!!!!!  This is one of the best beginner hiking trips you could take (not that you're a beginner).  We have tagged this trip as the first trip each of our kids goes on when they start backpacking.  It's challenging but not too technical and absolutely gorgeous.  We were just talking about going back the other night.