Our family's favorite way to get to the Magic Kingdom is to park at the Wilderness Lodge and take the boat from there straight to the Kingdom. You get to walk through the awesome Lodge and don't have to fight the crowds at the Transportation and Ticket Center (There's no parking at the Magic Kingdom, everyone parks at the TTC and takes either the Monorail or the big Ferry). Be prepared that Disney frowns on this tactic (just think if everyone tried to do that!). Simply call the Wilderness Lodge asap and make a breakfast reservation for that morning. Tell the guard that as you arrive to the parking lot and he'll let you in. Then just don't go to the restaurant (there's no penalties for not showing up). Or, you can tell the guard that you're shopping or that you're doing a tour of the hotels. (every my family does a big hotel tour on our first day of vacation. most of the hotels are worth a visit unto themselves and it's totally free. :D )
Since you're driving, print up Disney's official road map. It's a life saver since many of the roads will do weird things for no apparent reason. http://www.disney.co.uk/usa-resorts/wal ... wdwmap.pdf
Favorite place to eat is Cosmic Ray's Starlight Cafe in Tomorrowland. It' sorta cafeteria style (good prices) and has an awesome singing alien in the main room. He does a great "lounge singer" shtick. :D Second favorite is the Liberty Tree Tavern near the Haunted Mansion. I do believe it's a reservation place, so call asap if you want to eat there (you don't have to wait til the day you arrive to make reservations).
When we first get to the park, we make a bee line for splash mountain and get fast-passes. Then go to big thunder mountain and ride it twice (or once if the place is long by the time we get through it once). Then we go ride splash. Be prepared that you might get wet or at least might end up sitting on a wet seat. Then we hit Pirates and the Haunted Mansion.
Good places for a breaks are the shows. The Tiki Birds and Country Bear Jamboree are nice. The hall of Presidents is closed for updates. Hmm, I think Space Mountain is closed too. Also, if you want some piece and quiet, you can ride the raft over to Tom Sayers Island. Fewer people there and there are places to sit in the shade and nap. They used to sell food on the island. Not sure if they still do so you might want to ask a cast member when you arrive.
If you want to do the Jungle Cruise, get fast passes for it instead and then go hit Splash and Big Thunder. The lines at the JC tends to fill up real fast and it can be a loooong wait. Don't attempt to stand in the regular line in the afternoon if it's hot out.
Notice that I didn't mention any of Fantasyland. We tend to avoid it like the plague. The rides are quite dated and the lines tend to be horrible (both in time and in the fact that the area around the line is boring. Newer rides tend to have things around you to provide a pleasant distraction while in line). One exception is the 3D movie called Mickey's PhilHarmagic. Good show. Boring wait though. Since you've got a little one in tow, you'll likely have to make a concession or 2. Maybe even split up the party so the bigger kids can skip the boring stuff.
And I'll PM you my phone number. Feel free to call anytime if you have a question about disney.