Avoid the very cheap made-in-china ones, they only last one season and are very rough, in my experience. Get one as large as you can afford. Easy cleaning is very important, I like ones that have a big enough door to get at least my head and shoulders inside. I haven't had much success with coops with a removable floor for cleaning, they tend to stick once they have a layer of bedding and poop on them. I've kept chickens for 20 years, there are 5 in my garden at the moment and I've been through quite a few different coops. I haven't tried the plastic ones, they seem very expensive to me.

Thanks
but how big for the coop?

If you err on the large size that leaves you able to get another chicken or two should you become addicted...

thanks all but i am going to build one and just needed some idea of the layout

If you have a large pet store within reach you could have a look and see if they have anything that gives you an idea

I found this on the web if its any use to you:

The rule of thumb for 4 chickens would be 16sf of walking space in the coop and 40 sf in the run for 4 standard birds. They only need one nest. A lot of factors can affect that, though, and chickens do live in less without a problem. In a comfortable run and temperate climate, the coop size might be fine, if they spend most of the day outdoors. If they want to stay in more during the day, say because of a lot of snow, the 16 sf might be small. Covering the run might make more area available to them. If they have some free range time, outside of the run, that also affects things. Different people find that different arrangements work well for them.