I have some Oak trees, Ash, Sassafras & Yellow Birch when is the best time to cut them for staves... Can I start to lay out the bow, maybe even get it floor tillered add reflex as it seasons/dries

You can cut them now but if you wait a month or so, the bark will be easier to peel.  I like to get a green stave roughed out and thinned to where I can bend it about 10".  I also leave the stave full width for the full lenght so I can adjust layout after it dries. The key is getting it thin.  For the whitewoods, you might want to stick with 5/8" all the way across the stave.

QuoteOriginally posted by John Scifres:
 For the whitewoods, you might want to stick with 5/8" all the way across the stave.

5/8" wide????

That would be 5/8" thick.The handle area would be best left at 1 1/2" thick depending on how thick you like your grip.

Is it best to remove twist or apply recurve into the stave while roughing it out green, or is it better to wait until later?  

Thanks, Howard

You can steam green wood.  Or tie it to a form to dry.