The first step as you mentioned is to have air circulation. Blue stain from what I understand cannot be removed once there. Some actually like the look it can create. The mold can be stopped by spraying with a 10 percent bleach and water solution. I've read where more than 10 percent bleach was no more effective than 10 percent. I had a mold situation once on a freshly peeled spruce, and the 10 percent bleach solution in a sprayer cleaned it right off, and allowed the surface to dry enough that it did not form mold again. Sounds like your timbers were pretty freshly cut. Stacked properly, it shouldn't take long at all for the outside surface to air dry enough to no longer be a problem, but keep in mind they should be stored so that they are not being re-wet by rain, and continue to get air circulation. Keeping them humid under a closed tarp would not be good. In addition, you would want to keep them out of the sun or as much light as possible to prevent graying. I'm lucky in that I have an old big dark shed with a concrete floor. My spruce in there still have as good a color as when I put them in there almost 3 years ago.
