This is a bit like the blind leading the blind. I'm not really sure, but you could start with 5-10 and see how that works for you. You will burn them off during your strength training (you don't need carbs before cardio work). So I think it also depends on how hard you are pushing yourself. I think the recommended form is dextrose, but I haven't worried about what kind of carbs to have yet. A lot of bodybuilders eat Smarties (the candy) before their workouts. I've tried a few things, mixing in half a banana in my strawberry Atkins shake (that's wonderful!). I also just ate a banana one day and that worked well for me. It's more like 15 carbs, though. I've mixed in cranberry juice a couple of times too.

Oh, one other note, a lot of folks think you need carbs immediately after the WO in addition to the protein. Men do, but some women gain fat when they do that. So if you do have carbs afterwards, just keep it low.