No lines at all, bgraham, because the 10,000 people ahead of you are already in line for the rides...
Get to MK at least 45 minutes before it opens...unless you have any little kids in your party that have to see the Welcome Song on the train station, move to your far right and and as close to the entry way as you can...you can even go past the entry way and then move back toward it in front of the other 10,000 people waiting in one giagantic mob to get in.
Make sure you leave yourself enough time to get over to MK by Monorail or by Boat, as you will not be able to park your car at MK itself. YOu have to park at the transportation center and add 30 -45 minutes for that ordeal.
This is now peak time at MK. Don't arrive after the park opens unless you don't really want to ride anything and are willing to get a few fast passes for the day.