My kids love potato wedges. Usually I use onion soup mix with a bit of oil. You can also use ranch salad dressing mix:
1 envelope ranch salad dressing mix
Preheat oven to 400 degrees. Cut potatoes into wedges. We've done both skin on and skin off. Coat the potatoes in a bowl with the ranch dressing. Line up on a greased cookie sheet. Lightly spray the potatoes with cooking spray. I use butter flavor. Cook 20 minutes, toss with metal spatula and cook for another 20 minutes.