I've brewed one Midwest Supplies Irish Red Ale strictly to the instructions. Now I have a Austin Homebrew Double Chocolate Stout that I added a .5lb of lactose to during the last 5 minutes of the boil. Now I have a Pumpkin Ale that I'm tweaking by adding a few more spices to make it like pumpkin pie (the kit only included brown sugar, cinnamon, and nutmeg).
Basically what I'm getting at is yes it's a great idea to follow the directions at first, but don't be afraid to experiment. I lurk here, Google what I don't know, and use a variety of consulting resources (i.e. books) to get an idea of what to use and how much. I feel as though I've learned much quicker since I'm not afraid to tweak, and I've already got my own from-scratch American Pale Ale recipe that I'm making soon with some spicy Hatch Chiles :rockin: