My good friend @badgerpendous has just posted his miscellaneous coop notes that's a nice list of "if I'd known beforehand, I would have..." items for all you newbie DIY coop-builders out there.
Once you get to his blog, you can see the rest of the coop updates to see how the process played out over time, but I really like the lessons-learned list.
See, before we got our own pre-fab plastic Eglu, I'd entertained the idea of building a coop from scratch. It didn't take me too long, however, to realize that the amount of time, tools and raw materials I'd have to buy would approach the cost of an Eglu, so I went the pre-fab route.
Without a lot of budget discipline, you can easily clear $400 building your own from scratch, not including the price of books to help you plan.
While there are a lot of great books out there with fabulous plans to use to build your own, I'm a man who knows my limitations. And the price I pay is to get some serious chicken coop envy when I see setups like that at badgerpendous or over on greenfrieda's blog. (sometimes I'll even window shop by searching on "chicken coop" on Flickr)
Edging away from building your own? If plastic's not your thing but you're looking for a high-end easy-to-assemble coop, you can also check out the offerings at Henspa.
Whatever you do, make sure your chickens get the right housing and you'll be rolling in eggs for a good long time!