How do I tell if a rutabaga is fresh? I recently bought a rutabaga from the store, having never done so before, and every single one on display had an oily feel to it - not sticky, but slick like it had been coated in a soft wax.  

Is this how a rutabaga should feel when it is purchased?  If not, what should a rutabaga feel like, and how can I tell if it is fresh?
That is wax, it's done to help keep the moisture in the root. Turnips are also.

You know it's getting along when it gets soft and spongy or when the skin starts to wrinkle, same with turnips, beets, parsnips, carrots....You pretty much can tell whether they are good or not in exactly the same ways. Are the firm and crisp or soft, flabby and spongy?