Methods for telling gender at a week old are not very accurate. You will have a 50% chance with these methods. The best bet is to buy sexlinked pullets or purchase as pullets from a hatchery or feed store. That is 95 to 99% accurate
This article is a good for some general guidelines to follow for chickens overall. Once you pick a specific breed, you can do more in depth research on what to look for when buying your chickens.
