Sindea, I just saw this thread and thought I'd offer a few other things in AZ. I lived in Phoenix/Scottsdale for 13 years....(I'll be there in March as well, visiting my mom who lives there 4 months every winter)
Spring Training games are great fun - good choice
If you're doing the Grand Canyon, try to make one of your routes through Sedona AZ - and take Hwy 83?? up through Oak Creek Canyon - spectacular scenery! You'll recognize Sedona as it's a much photographed part of the world - if you have time and $ take a jeep tour there, they will get you out in the red rocks for even better sights! Also in that area, for the scenic way back to Phoenix, a trip through Jerome AZ is always fun, very artsy quaint community - fun shopping.
In Metro Phoenix, if you've never been out west and have small kids, a trip to Rawhide, very touristy, but fun for the kids. A unique restaurant up in Carefree Az would be Pinnacle Peak Patio (talk the hubby into wearing a tie - they'll cut it off at the door) another unique restaurant. Then, for VERY LAID BACK atmosphere, and if you like to have a few beers, try to find Greasewood Flats. It's a fun "bar" which is outside and very "western" - wonderful to enjoy AZ in March. (if you go early, it's OK for families) If you want to take in some of the wonderful 5 star resorts, I'd recommend going to Hyatt at Gainey Ranch. That resort is just spectacular to just go walk around the grounds, have a coffee or wine in the bar. (my hubby proposed to me there at one of the Italian restaurants) AZ sure does resorts the best I've ever seen. For wonderful city views, The Pointe at(not Squaw Peak, nor SOuth Mountain - I can't for the life of me remember the name of it (our wedding night was spent there - Tapitio Cliffs??)- off 7th Street) the resort sits up on top of a Mountain (well, Phoenix type mountain) and the views are spectacular - again, enjoy a dessert or wine or something up there - or just go take a look! In downtown Phoenix there is a restaurant which sits on top of one of the high rises, and goes around - also great views. SOrry some of this is kind of vague - my memory just went blank on the names. I just thought I'd steer you in some unique to the area sights, and so you don't end up at Applebee's
. A lot has changed in the 5 years since I've lived there, but I'm sure what I've mentioned will still be there. PM if you're looking for any more ideas. If you're staying in Tempe, you'll be close to LOTS of things and freeways to get you anywhere. Old Town Scottsdale has very unique shopping as well. It's just all so beautiful - I miss all the beauty (don't miss the traffic) Have a great trip, I'll look forward to your LO's from the trip!