Solid Green Knowledge Search is a custom search engine that aims to search sites that provide solid info and analysis. Unlike some of the other custom searches on Appropedia, this includes copyrighted as well as open licensed information.
Use your judgement, as the info may still be wrong. (And we still need to separate out subsites that may contain different types of information - that's a slow process.) It was first created 5 January 2011, is in Public Beta - it's usable, but in the early stages of choosing suitable sites.