Unless you have a pro who can vent sex the newly hatched chicks, it will take a while to know what gender they are. By 6-8 weeks, the comb and wattles will often tell you what sex the young birds are-- larger, more red combs and wattles indicate males. Often, but not always, the male chicks will show gender specific feathering by 13 weeks or so. Those are the main things to look for.
However, there are some tricks, depending on what breed and variety you're raising. In some color patterns the coloring will be different for males and females, and those breeds are easier to sex early.
There is also the option, once they grow feathers, to send in samples to a lab, which, for a price, can tell you the gender of the bird after testing.
These are just some basic things to keep in mind. Generally on this board, 6 weeks is the very earliest age to send in pictures to get help with sexing.
