Yeah, MikeB--what Zeek said!
Dust 'em off and scrape your fingernail gently across the edge. Does it scrape off a layer? If not, the edges could be sharpened.
Run your fingernail lightly down the edges. Are there rough spots, burrs that catch your nail? If so, the edges could be smoothed (a "gummi stone" is great here).
Were your skis tuned in the first place? Put a metal-edged ruler flat across the base and shine a bright light behind it. If the base is not flat, you will easily see it this way. Is the base concave or convex? Do the edges protrude beyond the base ("railed")? If so, your skis should be stone ground or, if way off, belt sanded and stone ground. Then the edges should be "beveled" according to the manufacturer's recommendations, unless you have your own preference.
Were your skis waxed? Ideally, you would have ironed on a thick layer of wax to protect your bases in storage. (But you probably didn't--neither did I!) If so, scrape it off to a very thin layer.
Most importantly, it is a good idea to have your bindings cleaned, lubed, and checked by a certified mechanic with the right testing equipment. Even if they were brand new when you put them away, it's a good idea to make sure the release settings are as they should be. If you backed down the spring tension over the summer (a good idea to prevent metal fatigue), they will need to be reset and checked. If you did NOT back them down, they should especially be checked to make sure they release according to specifications.
If you don't have one, buy a little fine-grit diamond stone from a ski shop and learn to use it to quickly touch up and smooth your edges. It only takes a minute. If you check and tune your edges daily, your skis will maintain a consistent tune always.
Same with wax. Have them hot-waxed (or learn to do it yourself with an iron--it's easy). Then use one of the many good wipe-on waxes daily to keep the bases running smooth and protected from "drying out."
Learning to do basic tuning on your skis is not only rewarding, but takes little time and will keep your skis in much better condition all the time. The question "how often should I have my skis tuned" doesn't have an answer! The real answer is "constantly." KEEP them tuned. Don't let get them get OUT of tune. Again, it only takes moments a day, and you'll ski better for it!