I've been tempted to do the same thing. I have a pretty thick book of darkroom recipes. Be sure to let us know the URL when it gets up. A special area where people can put contributions, subject to your editing before they join the main list, might be an idea. Given the number of things that no longer work terribly well and given the high likelihood of errors in published and copied formulas, you should probably include a disclaimer that the recipes are not guaranteed to work and that, although taken from the best information available, the formulas also can not be guaranteed.