Proper usage guidelines and examples are appreciated.
Odor has a few meanings that scent doesn't:
Conversely, scent has a few meanings that are not covered by odor:
Also, scent works as a verb, while odor doesn't.
For further details and examples, see:
For finding more sample sentences, I refer you to these resources.
"Scent" can be positive -- there's the scent of a skunk, but there's also the scent of a pretty girl's hair, the scent of jasmine or of honey, the scent of your favorite spice -- but "odor" is neutral-to-negative. Try telling a woman that she exudes an interesting odor; let me know how that works out.
Metaphorically, "odor" means "characteristic" or "reputation". They used to say "odor of sanctity" but in keeping with the generally negative connotation of the word, that phrase has disappeared, while "odor of corruption" remains.
"Scent" as a metaphor has the association of a tracking dog. There's the "scent of mystery", the "scent of a bargain". Someone who wants attention is "giving off a scent" and someone who is in the process of solving a puzzle is "on the scent".
I remember getting off the plane in my favorite Asian country, having brought my wife to visit for the first time. I took a lungful of air -- a familiar, missed mix of cilantro and lemongrass and palm tree. It had been many years and I was happy, moved, to be back. My wife wrinkled her nose. "Smells funny here."
That's the difference between "scent" and "odor".
The Merriam-Webster entry for "odor" contains:
According to that definition, an odor can be a scent or a smell.
The dictionary then gives two examples for "odor":
The entry for "scent" has the following examples:
Based on the definition of "odor" and on the examples, while "scent" is always associated with a living being that produces the smell, "odor" can also be associated with other smells (e.g. as the ones produced by cheese and that the deodorant prevents in the examples above).