+11
I agree. I hadn’t realized how old that book is, though, until I picked it up recently to refresh myself on a couple of styles. Regardless, what I think is great about it is the way he provides the commonalities and differences between a variety of beers of the same style.
When I first started designing my own recipes I used a similar approach of taking three or four recipes from quality sources (mostly BYO at that time) and looking at the similarities. Which base grain is appropriate, which hops, etc. Then, tweak it over time to get what you want.
Major’s advice is solid, but I also think you need a guide - especially when you’re starting out - to help you determine which base malt or hops or clean ale yeast you want to use in the American Pale Ale. Particularly if you want to stay on style.
Of course, I’ve also done a bunch of crazy beers where I’ve just throw together whatever I had and they came out pretty good, too.
Before you start trying to design recipes I would highly encourage you to learn more about the ingredients available to you and what characteristics they add to a beer. Either brew clone recipes of beers you like so you can see how each of the ingredients transform into a final product where you know what the final product should taste like and/or brew very simple recipes with one hop and extract or extract plus one specialty malt. You can also read as much as you can but you also want that sensory perception.
It’s easy to want to get right into recipe building and it can be done but your future recipes will benefit from taking a few batches now and just keeping it simple to learn the ingredients. Otherwise you risk being another one of those people on some of the larger forums asking questions like:
“I want to brew this stout but I don’t have any roasted barley. Will it be ok if I use this pound of honey malt instead?”
or making recipes that use every grain available in the LHBS because it was available. Your beer just doesn’t need 15 different types of grain.
Unless you are brewing a clone of Jewbelation 15. 
I tried to make that more accurate based on my own experience. You might only need one or 2 grains for what you want to make, but OTOH you may need many more.
Just like food. Simple is great, but then there’s curry.
I almost always start by looking up the recipe in Brewing Classic Styles. The book also talks about what characteristics are important to get right. Then I look around at other sources. I’m skeptical of recipes off the internet. I use them, but I always look at who provided it. The recipes on some user-contributed sites are all over. I’m pretty sure there’s a Kolsh recipe with chocolate malt out there somewhere.
My method for a style I haven’t brewed as well. I like the chocolate malt in kolsch reference - I don’t doubt it. There was a time with the early internet “beer recipe databases” that that might have been the semi-norm. 
Hey, I used chocolate wheat malt in a Kolsch last year! Only I didn’t call it a Kolsch. I called it an American brown ale. But used WLP-whatever-it-is. That 2565 yeast is too much of a pain. But we digress…
My process has been think of an idea and try and build a recipe via the suggestions in the BJCP Style Guidelines. Then ill refer to literature to check for accuracy and anything i missed. ill brew these and then refine from there.