Source: Lois & Clark: The New Adventures of Superman seasons 2-4 (1994-97)
Whalin had this to say about the character when he was cast: "In the comic books, Jimmy wasn't nerdy at all. He was out of reform school and an orphan. That's where I based him. He's more streetwise. He has to have that excited energy about some day wanting to become a reporter. He worships Perry, Lois and Clark. He's eager, but not nerdy." That's not a bad summation of the character, actually.
Of course, he wasn't the show's original Jimmy. That honor goes to sweater-vest wearing square Michael Landes. But that's a story for another day.