Go watch the first 8 minutes of the Pixar movie Up. Not a word said, but when I saw that every adult in the audience was on the verge of tears. The same with the incinerator scene in Toy Story 3. Why?
The stories touched us because of a familiarity with our own experiences and our emotions. Up provoked thoughts of our grandparents or parents or even our spouses and the struggles that are inevitable in life. Toy Story 3 made us think of our friendships in life. Both appealed to our more noble inclinations. We wanted to be a better version of ourselves. We saw a reflection and in that reflection we found meaning.
Putting emotion into your magic is easy to do badly. It is easy to be trite - an ambitious card routine that talks about always being able to rise above adversity. When you say the message it loses its power. The key is doing it subtlety. You want the audience to have to think to get the message. Think about how parables work - they illustrate the message without saying it.
The other problem is the magic not being strong enough to withstand the message. It is harder with card tricks because they are trivial magic. There isn't much meaning in an ace assembly or even a matrix routine.
Finally, your character needs to be able to support an emotional presentation. A trickster who presents every effect by narrating the adventures of the props cannot all of a sudden become serious and thoughtful.
Let me give some examples from my repertoire. I have a routine using worry stones (based on a Eugene Burger routine using prayer beads) that talks about worry and prayer, quoting the pop star Jewel, a Russian philosopher, a Dutch theologian and my mother. The message is that prayer changes the person who prays. I have a kids linking rings routine that tells the story of a young dragon who falls into a rock crevice and can only get out by linking the rings together by using the dragon fire that is within him. My egg bag routine is about a girl named Margaritte who lived with her mother in Nazi occupied France during World War II. A German Sargent comes by every day demanding she give him the eggs her chickens lay. She wishes that the eggs disappear and they do. Then she finds out that the Sargent isn't quite like what appears to be and she uses her magic to help him feed some orphaned children that he is taking care of. I've written a script for a Sands of the Dessert routine talking in the abstract about how life becomes clouded and confused. Then I rewrote the script to talk about a time in my life where I found myself lost and confused and seeking clarity. Personal experiences are so much more powerful. I do a haunted key routine based on a story about an armoire in the upstairs bedroom in grandparents house that used to really freak me out as a child. I'm working on a needle swallowing routine where I juxtapose a series of bad puns with the macabre idea of swallowing needles and washing them down with a glass of wine. The combination of the familiar (a glass of wine at the end of the day), with the macabre (swallowing needles) and the ridiculous (puns) has the audience in a state of unease.
With emotion, the advice of the late great Eugene Burger is soo important: a show should have texture. There needs to be a blend of serious, whimsical, thoughtful, funny, heartwarming and, yes, even disturbing emotions. My goal with my shows it to give the audience something to think about and talk about afterwards. I remember one woman who came up to me after a show and asked me to repeat exactly what I said in one routine so she could get it exactly right when she told her husband that night. The benefit is that the audience remembers your magic in the context of the presentation.
As for books, read anything by Eugene Burger, Robert Neale, Larry Haas, Walt Anthony and David Parr.