If you throw in one or two tales during an adventure, the players will know it pertains to the adventure or the next one. Every barkeep, barmaid, shop owner, and cutpurse has some rumors to relate. Most travelers, adventurers, heralds, and guardsmen would enjoy exchanging news of places they have been. Sages and bards are full of stories, legends, myths, rumors, and tales to relate. Dragons and other intelligent creatures are storehouses of information.
Priests are full of prophecies, and wizards are stuffed with arcane knowledge.
Political scandals, tales of lost treasure, and rumors of strange happenings make for hours of listening. Old, out of date rumors can make the rounds every so often. Tales of heroic feats and legends of powerful adventurers inspire young people to take up swords and spellbooks and seek their own destinies. Rumors of trouble can precede invasions. There are so many possibilities, use your imagination.