Bird-sign/Augury/Ornithomancy Resources?

I've managed to get a general idea of bird-sign since there are so many birds in north California and it would be silly not to learn it. However, my knowledge is still very limited since most of the websites I've found only tell me what the bird itself means.

Occasionally I get specific situations and what it means when they fly south/north or that matter, but the majority of websites limit it to a list of birds + meanings, often in a huge wall of text that makes my eyes glaze over.

Does anybody have books or reputable websites that they'd recommend?

[url=http://www.ecauldron.com/forum/showthread.php?2868-Bird-sign-augury-ornithomancy-resources]Bird-sign/augury/ornithomancy resources?[/url]