12/03/2008 at 11:40 AM EST
has a solid relationship with Dallas Cowboys quarterback Tony Romo and a hit country album, Do You Know
But the singer still thinks she could use some self-improvement.
"I am the first person to go to Barnes & Noble and buy the new self-help book," Simpson, 28, tells Marie Claire
in its January issue, on stands Dec. 9. (In the story, the cover girl reveals things people don't know about her.) "I like to fill out the surveys, then I get my friends' opinions on how I answered to see if I was being honest with myself or not."
But self-help titles aren't the only books Simpson is interested in studying.
"I've been contemplating taking a college course in religion," she says. "I love religion. I remember whenever the book The Da Vinci Code
came out, the Discovery Channel did this three-night piece on it that I TiVoed and then watched eight times."
And while many performers rely on staple superstitions such as broken legs to bring them good luck, Simpson takes a simpler – and less painful – approach.
"I collect lucky pennies that I find on the ground," she says. "I keep them in a Ziploc bag."