What is your purpose for having chickens? Eggs, pets, etc?
Assuming eggs, then go for high production breeds. Sex links (black or red), Australorps, Barred Rocks and Leghorns are breeds that are great layers. Easter Eggers (often sold as Americana) are mixed breeds, and while some do lay blue or green eggs, they can lay any color egg. So it's not a guarantee. If you want blue eggs, look for Cream Legbars or pure Ameraucana's (notice the difference in spelling from above). Mixed breeds, like sex links and Easter Eggers tend to be my best layers.
You can also choose on what is visually appealing to you. You are going to be spending a lot of time with them, so you want something you enjoy looking at. When I started with chickens almost 8 years ago, I got a Buff Orpington, Sicilian Buttercup, Easter Egger, Barred Rock, Red Sex Link, Light Brahma and a Production Red. I still have my Light Brahma, though she hasn't laid in years now.
Welsummers or Marans will give you darker brown eggs.
I can only suggest that you research the breeds and choose what you think you will be happy with. Welcome to BYC and have fun picking out your birds!