I will use Lord of the Flies as an example. Consider the shell. Denotation- the shell has monetary value. Connotation- the shell is valuable for its ability to call everyone together, and is therefore a symbol of leadership and civilization.
The term "man" is explored in Huckleberry Finn and might be a good book to examine for connotation and denotation.
Another popular piece of literature with moments of contextually defined meaning is Julius Caesar, with numerous instances of word play related to connotation.
I think knowing and understanding the definitions of and differences between connotation and denotation will help you locate examples in any book you are currently reading.
Both of these literary terms fall under the "diction" category. Diction refers to an author's word choice. Sometimes authors choose certain words for their denotation, or, exact meaning. Other times, authors choose words for their connotation, which means the associations that are present with specific words. Using words for connotation is usually done figuratively, rather than using the literal denotation of a word.
A general example (not necessarily from literature) to show you the difference is this:
It isn't my fault I failed the test. I sit behind a porky girl who blocks 50% of my view of the board.
The connotation of the word "porky" in this context is anything that is synonomous with "fat" or "pig-like." Realize here too, the connotation of "porky" is negative. I am blaming my failure on this large girl because she prevents me from seeing the board.
In another context, porky could be looked at for its denotation:
After simmering the stew for more than 4 hours, the flavor will fully infuse the bland navy beans, giving them a rich aroma as well as porky taste.
In the above example, "porky" means exactly what it suggests, like pork.
Anytime an author uses language suggestively, rather than literally, likely you are witnessing an example of connotation over denotation. Hope this helps.