Do It Yourself Sprinkler System
Even the most adventurous do it yourself home landscapers are a bit intimidated by the thought of installing their own sprinkler / irrigation systems. I can understand this. It does seem a bit technical and involved.
However, with the free and cheap sprinkler information that's available to you, there's really no reason why you shouldn't tackle the technical side of installing your own system.
Your only real consideration should be the labor involved. Mainly, using a trenching machine. While you can rent a trencher at your local rental outlet, these machines are heavy and require some strength to move them around. In loose soils they have a tendancy to get stuck and require two people to get them out. If possible, get a four wheel drive trencher. Ask your rental agent if they have one.
As for the technical stuff that you're probably looking for?
While I've designed and built many sprinkler / irrigation systems, I think that creating a high quality free do it yourself design tutorial is better left to someone that's already done it.
Irrigation tutorials.com is by far one of the best free information sites on the net. Using the site should leave you with very little question on how to design and build your own irrigation system. You'll also discover more resources and sprinkler material deals in The DIY Landscape Design Directory.
I hope this helps.