The photos came from Google image searches with the "large" size selected in the search filter. I saved each photo on my iPad and put them in an album to make flipping through them easy. You could also use magazine clippings. Or just read a list of names without using photos, but guests who don't know what a particular celebrity looks like will be at a disadvantage. To find the ages, I just Googled "[celebrity's name] age" and it popped up at the top of the search results.
Guests could number their own pieces of scrap paper. Or you could get all fancy and make your own answer cards personalized with the guest of honor's name, which is what I did.
I also made this generic version in case anyone wants it. Download the game card PDF here.
It turned out to be really fun. Alex did fairly badly, which was even better. It's good for some laughs! I had no idea Keanu Reeves is 48.