Hiya,
Some rides in DLRP have fastpass - this is a separate queueing system for the ride. You use your park entry ticket, put it in the fastpass machine next to the ride of your choice, and it will print out a fastpass ticket for you, which gives a 30-minute time slot for you to return to the ride, and use the fastpass queue. It cuts down queueing times basically.
We are not big coaster nuts, but we find using fastpass for the Peter Pan flight in Fantasyland, Buzz in Discoveryland, and Big Thunder Mountain in Frontierland, cuts down our queue time considerably.
Going in June, and if you make good use of Extra Magic Hours each morning, you may find you've had your fill of Peter Pan and Buzz by the time the parks officially opens at 10am, and so you might not need to use fastpass with these rides at all.