Everyone gave you great advice, and of course, welcome to BYC. You know, if your luck runs like mine does you may not have to look for a rooster. You said yours are babies. Unless they are sex linked (which means that males and females look of the same breed or variety LOOK totally different when hatched) you may have one right under your nose! For example, Golden Comets (or Red Stars, Red Sex Links and several other names for basically the same bird) are sort of yellow with buff colored backs. The roosters are soft yellow all over. That's a sex linked trait. Same with Black Stars (or Black Sex Links). One sex will have a white spot in it's head, but I'm doggoned if I can remember whether that's the boy or the girl right now!
Little chicks are notoriously difficult to sex, as you can see by the number of posts asking what sex this chick or that chick is. Even though I bought all girls at a feed store last year, out of 6 supposedly female chicks straight from the pullet bin, I got 3 roosters. Yep. And when I ordered a dozen eggs to hatch under my broody hen, I got 15 from the shipper. One egg hatched. It was a rooster. So how old are your little ones, and do you know what kind they are? How many do you have? You might have a roo right now and it's simply too early to tell. It would help if we knew what kind of chicks you have.