The Disappearance of the Universe, by Gary R. Renard. It is a very approachable explanation of another book, A Course in Miracles. It is the first thing that has ever succeeded in budging me from my fundamentalist Christian views.
Yes, it's normal. Low productivity for a newbie is pretty standard. Even if your programming chops are fantastic, you come into a new job knowing nothing about the domain they are programming in, which may be very complex and have a long history, and nothing about the tools, the code, the architecture, and so on, which may (and often does) suck. I am seeing this right now with a new hire where I work. She's competent, but just drowning in all the stuff she has to learn. I was here when our system was and designed and built, and I did a lot of the designing and building myself, so I have a deep understanding of how it works, an understanding that I think would be incredibly hard to come by second-hand. It can take years to become fluent in a big system.