"I'm trying to read as much as I can, and prep as much as I can," Harris, 37, told Ryan Seacrest before Sunday's Emmy Awards. "But there's only so much you can do because each baby is super individual and totally their own person."
The How I Met Your Mother star and his partner David Burtka recently announced they are expecting twins, with the help of a surrogate, in the fall.
"[I'm] very, very excited," the two-time Emmy winner said. "It's the big, crazy calm before the ridiculous storm."
But already fatherhood seems to be agreeing with him. In fact, Harris was advocating it for Seacrest, who noted Harris's busy work schedule recently.
"Life goes on, Ryan," he said. "If you wait until you're not working to have a family, we might be waiting a while."
Joked Seacrest: "Tonight, I should start trying."