How can I store stored chicken of the woods?  Last year I tried dehydrating but it really doesn't bounce back too well. Could these be sauteed and then frozen for later use in sauces? They only come around once a year so I don't want to screw them up this time.    
The baking time doesn't really depend on the weight. It depends on the thickness, and how well done you want it.  The FDA recommends cooking to 145F, but you'll probably find it a lot nicer in the 120-130F range. There's a lot of room for personal preference, so it's hard to be too precise. It doesn't need to be held at the temperature for any length of time. Once it's hot enough, it's done. If you don't have a thermometer, you can also simply check it with a fork, to see if it flakes apart easily.  I might try 425F but 450F would work fine too. Assuming you're baking it uncovered on a sheet, for typical filets around 1 inch thick, I'd guess 10-15 minutes. If they're extremely thick, maybe 15-20. But since it's so easy to overcook, and so much better when it's just barely cooked enough, and ovens aren't terribly precise, you should definitely just check early, rather than relying on a timer. 