Expectant Dad Pete Wentz Is Reading Up on Fatherhood

By Hilary Shenfeld and Stephen M. Silverman

08/04/2008 at 03:15 PM EDT

Having already admitted that he's turning into his own father in anticipation of the arrival of his and wife Ashlee Simpson's baby, Pete Wentz tells PEOPLE that when it comes to prepping to become a parent, "I'm reading a lot of books."

The Fall Out Boy bassist, 28, at his Angels & King nightspot in Chicago with Ashlee nearby, explains, "The biggest one is The Expectant Father. It's a really good one."

Not that the printed page is teaching him all he needs to know. Jokingly, he adds, "Also, I've watched Look Who's Talking and Look Who's Talking Too. I'd be worried if the baby sounded like Bruce Willis."

As for wise words from his father, Wentz says, "The best advice my dad has given me was, go with your gut. And he said you can't really have expectations. If I have expectations that he's going to be a rock star, I'm sure he'll come out being into sports, and if I have expectations that he'll be into sports then he'll be into math or something."

Having digested that, Wentz says, "I'm just going into taking it one step at a time, and I'm just excited to meet the baby."

In terms of further preparations, "We'll baby-proof the house," he says, "getting the nursery ready." Regarding its theme, "It's not a secret, but it's more of a private thing. I haven't really figured it out yet, so I don't want to go out there and say what it is and then have it not be that."

Nor, when asked if the nursery is pink, will he divulge a color scheme. "Contrary to the stories out there, we don't know the sex of the baby," he says. "I'm a person that always likes to be surprised, so I like to wait for the surprise."

In the meantime, he says, "Ashlee's a trouper. She's been really good with this. She's probably one of the most health conscious, spiritually free pregnant women I've even been around."