Adobe have recently released a new document on devnet cumbersomely titled the Adobe® Flash® Platform ActionScript® Reference Rich Internet Application Development also known as the AFP RIA Guide or Every class in a book. You can get the free, CC licensed PDF here.
http://www.adobe.com/devnet/actionscript/articles/atp_ria_guide.html
Which version of actionscript does this cover. we are a new york based web design company.
Player 10, air 1.5, flex 3. Presumably they will update it when future versions change.