The BTO have a new guide published this month and I can heartily recommend it. The book has been produced to help those involved in nest finding for research and conservation purposes. Alongside 146 species accounts it contains useful information (for newbies like myself) on fieldcraft, legislation, the BTO Nest Record Scheme.
I just thought I'd flag this up as it may be of interest to any trainees who, like me, have always been fascinated by the 'dark art' of nest monitoring, but have never really managed to get going.
Obviously there is no substitute for practice and patience, but this book (along with ye olde Observers Book Of Birds Eggs (Ebay it)) might be a good place to start.
Who knows, by next spring perhaps I'll be able to locate more than my garden blackbird's nest!