According to the serial number you gave,
this is a Waltham circa 1900 size 0s hunter case
pocket watch with a model 1891, Seaside 15-jewel movement.
You did not mention if it is gold or gold-filled (they made both).
A gold-filled (not gold) watch has a value of $150.00.
A 14k gold watch has a value of $300 in this make and size.
Some sites that I recommend for selling are Varagesale.com, Ioffer.com, OfferUp.com, Ebay and letgo.com.
You can also go to invaluable.com or liveauctioneers.com and search their directory for an auction house near you and consign to them.
To finish, I will need you to click the five stars at the top of your screen and hit the submit button, thanks!