Selecting the best breeds for your flock.

Helpful article!
Perhaps splitting up the dual purpose section to Dual purpose-egg layers and a second group called Dual purpose-Meat would be helpful. That way, you can put the Rhode island red into dual purpose egg layers group for example.

Nice overview for beginner chicken keepers

Overall a pretty good overview of breeds!

A few small changes, like moving Rhode Island Reds to the dual purpose category, since they are a dual purpose breed, would be good.

There are also a few grammatical errors, like for example the apostrophe in the "Eggs" section title.

My last suggestion would be to add some pictures.

I liked it when you noted your own experience! It is crazy you had a triple yoker!!!!! My only suggestion would be maybe to add a questions list of what the reader may want out of a breed. This will help them really get to thinking.
Great job!

Overall, a decent overveiw. I appreciate the recommendation of "orpington" instead of "buff orpington" like so many do. I believe the "cornish" you list in the meat category, you are actually talking about cornish X, they are different, so I recommend you edit that.

I would change "white or brown leghorn" to "leghorn"
and "Barred rock," to Plymouth rock.
"Maran" should be "marans," it is a french breed, so the 's' stays, even when singular.

I would also suggest adding Ameraucanas and Legbars to the "colored egg layer" category.

I may also suggest adding a "friendly birds" category for those looking for sweet pets. (Bantam Cochins, Silkies, brahmas, Ameraucanas, Orpingtons, etc... may go here.)

Or, since friendliness is much more dependent on the individual, and different people have different things that they classify as friendly, perhaps just an ornamental category: polish, silkies, bantam cochins, phoenix, d'Uccle, etc...

Really, we could sit here all day naming chicken breeds, I think you've done a great job giving people a starting place, the only other thing I would recommend is including some photographs.

Leghorns come in more colors than white and brown and they are heat hardy but not cold hardy. Silkies are more of an ornamental breed than a colored egg layer. Ameraucanas would be a good alternative. Cornish cross should be mentioned along with Cornish in the meat category since they are the most common breed in the world, but also mention that Cornish Cross won’t live long enough to breed or produce eggs. I wouldn’t call Orpingtons dual purpose. Delawares or New Hampshire would be a better alternative. Hatchery Orpingtons have poor meat production and show Orpingtons are slow growing.