Visit your local library or bookstore, and you'll find loads of how-to books on furniture restoration. But don't let the seemingly simple directions and nifty illustrations fool you -- some projects are better left to experienced professionals. Just because you have the ability to restore a piece of furniture doesn't mean you should. The truth is do-it-yourselfers -- from novices to those with years of experience on home projects -- simply don't have the same caliber of resources as trade professionals, may it be training, technical skill, tools or an intuitive eye. Here are five furniture restoration projects that should be left to the pros because the risk of making a mistake just isn't worth it.