Believe it or not, we're ALL faking it to some extent. Whether it's feeling unprepared to start a job, rent an apartment, buy a car, have kids (yikes!!!), buy a new house, etc.
I know lots of teachers who don't feel like they know what they're doing until they're starting their third year. I know that I had one year doing library stuff before joining my current school, and after two years there, I *finally* know what I want to do with the collection and how I want to allocate my budget and deal with the students and other teachers and stuff.
It's definitely good that you're looking into trade journals and stuff. Even though we're all faking *something* to some extent, it's still good to keep learning!
So don't sweat it too much, just work on becoming more comfortable with your area. If you're not in a job yet, definitely see if you can get together with other people in your field-- see if you can tour a few places, or have a few lunches with friends of friends, just to learn more about the field.
Best wishes!