How often do I need to wax my skis?

Probably nothing will happen if you don't get them waxed, unless you skied last year when it was warm. If you skied when the snow was warm then there's a black sludge that builds up and really slows you down. If your ski bases are dry too the skis will be slower and may make turning a little less responsive. If you are out West wax and a ski tune needs to be done less often for soft powder snow, once a season maybe. In the East I like to get my skis waxed at least after a week of skiing, and I use one of those rub-on waxes in between shop waxes. Look at the bases, are they dry, are the edges rusty? If you don't have time now maybe the ski area offers quick tunes so while you are there you can get it done in their shop. Check at their ski shop or where they service rentals. For your safety try to get the bindings release checked too.