The GAO (Government Accounting Office) has a long and respected history of evaluation. Many luminaries at AEA (American Evaluation Association) have spent/are spending their professional careers at GAO. The GAO has just published (January 2012) their handbook on evaluation. It is called, DESIGNING EVALUATIONS 2012 Revision. Nancy Kingsbury, a longtime AEA luminary, wrote the preface. For those of us who receive Federal money in any form (grants, contracts, Extension) this will be a worthwhile read. Fortunately, it is a relatively short read (text is 61 pages plus another 7 pages of appended material). This manuscript explains the “official” federal view of evaluation. It is always good to know what is expected. I highly recommend this read. The worst it could be is good bedtime reading…zzzzzz-zz-z. 
Just screen thru the GAO Designing Evaluations 2012 Revision. Apart from a full set of inforamtion in evaluation desgin, it also gave some significant updates on a number of other areas such as program implementation and mothodological challenges. Thanks for the effort made. Assuming there will be an updated version for Evaluation Synthesis coming soon as the cuurent version is on 1992. Cheers.