This might be a long page on the research methods of Herodotus, were it not that it can be made short by just saying that Herodotus method lived out the notion that True is good, but interesting is better. A sentiment of the appeal of fiction genres, most prominently Hollywood and its historical films.
Mel Gibson's Braveheart set alight mediaeval forums. And 300 is a fantastic cartoon. I am grateful for the great productions and interesting portrayals of historical characters, and even the fictious ones, bound to generate healthy attention for history--however you got here, we don't ask how...
The people of the future in Stark Trek looked like mum and dad with a track suit. The genre quickly appropriated the ancient and the mediaeval and heroes started to look like fierce Spartan, Nubian, and Mongol warriors. Again, if an interest for Herodotus or other history awakens, via The Galactic Knights or some other war and doom blockbuster in the flicks, so be it.
Herodotus weaves interesting bits with the factual narrative with consummate style; you enjoy following each of his digressions, and marvel at the range of his enquiries. For being the first historian in this long profession, Herodotus could have done a lot worse, with not much in the way of shoulders to stand on. He actually hit it out of the park.
The elusive historical fact has many faces in Herodotus' Histories, some things he witnessed, others he was told, he saw inscriptions and monuments, talked to people close to the events and read and heard reports. Religion permeated Greek society; to be Greek meant to worship the same gods. The Histories contain religious content, superstition, and obvious fantasies. Herodotus plainly warns that he writes what he is told, though he needs not believe any of it. Sometimes he gives conflicting accounts he heard of an event and explains the merit in each.
Most remarkable is his tenacity to follow a story. The Pursuit of Herakles, as I call it, is a religious study contained in The Histories, Herodotus crosses the length and breadth of the Agean seeking to find out the extent of the worship of the god Herackles. His conclusion breaks with Greek tradition in a big way.
Herodotus shares much with Livy as a fabulous raconteur, and pays dearly for telling an entertaining story, something both Livy and Herodotus do effortlessly. Suspicion soon sets it, and a pall of mistrust hangs over the author. Taken case by case, much of Herodotus work, despite methods not wholly conducive to great confidence by modern standards, remains credible and archeology periodically validates things Herodutus relates, a prominent example, the Athos Canal, (Isserlin, 1993), a great feat of civil engineer Xerxes accomplished for the safe passage of his navy, using thousands to dig a canal and avoid the treacherous waters around Mt. Athos, which had claimed many Persian ships. Later writers in antiquity ridiculed Herodotus' canal and have been proved wrong.
We don't know much of the life of Herodotus, but readers of The Histories get to know him well, and the man that emerges from the pages, is not a trickster, but a serious and passionate researcher, member of the intellectual elite that laid the foundation of Western civilization.
It is obvious Herodotus consulted Persian sources, but one of the methods he refers to several times is the conducting of interviews.