I would like to try to apply the baker percentage concept to create my own baked good recipes (cakes, cookies, muffins, etc.). However, I can't seem to find any resources that indicate appropriate ranges for each type of recipe. I have found many resources that explain the baker percentage concept, but none that provide appropriate ranges. What are some good resources that explain baker percentages for various baked goods?
You are confusing terms here. Baker's percentages are used for bread and bread only. In pastry baking, ratio is even more important as in bread, but traditionally, nobody calles it "baker's percentages".
The book you want is Ruhlman's Ratio. It gives exactly the information you want for pastry and some other things (noodles, mayonnaise). About the only common ratio he doesn't explain is ice cream. It also has some recipes, but the main focus is on the exact proportions of flour, sugar, fat and liquid you need for each type of baked good.
Peter Reinhart's The Bread Baker's Apprentice gives baker's percentages for all its recipes.
In addition, if you have a source that gives weights, you can calculate the percentages yourself: flour is always 100%. Each other ingredient is divided by flour weight (then multiply by 100). So, if you have 500g flour, 325g water, that's 325÷500×100=65%. Alternatively, Artisan Bread Baking has a baker's ratio calcultor that'll do the math for you.
King Arthur Flour, Cooks Illustrated, give bread recipes by weight, so you can do the conversion.