> If it's a somewhat technical topic, go straight for the textbook/papers. If you don't understand them, you won't understand them any better from reading the "pop" material. If it's too complex (say, quantum physics), walk back and get acquainted with more basic material.
OK, I've been holding this in and now I finally have an excuse to put it out there:
Trying to talk about quantum physics without math makes it more confusing, not less. You inevitably end up making some weird analogies which aren't analogous, things which an expert might be able to reverse-engineer into the actual concepts but which put a non-expert in a Lewis Carroll Bullshitland, which is like Wonderland only not as amusing and definitely not worth putting in a book, let alone a "physics" book.
At worst, you end up with crap which is actively wrong, like everything Deepak Chopra has ever said in his entire existence.
Meanwhile, you can give people a real understanding of basic quantum mechanics with high-school algebra and a bit of simple logic.
The deep reason behind this is the same damned interpretation problem physicists have failed to solve for nigh-on a century now. We have the math, we know it works, and, miracle of miracles, we can do some real physics with fairly simple mathematical models, but we don't know exactly how the math hooks up with reality. If none of Dirac, Bohm, Feynman, and Pauling could definitively solve this problem, the odds of a pop science author doing so are not worth thinking about.
To drag this back to the topic: A book about quantum physics which includes no math isn't worth reading.