I moved into a new condo with washer/dryer hookups. The washer drain (where you place the hose) is still covered with plastic and there are 2 holes - one on either side of the hot/cold hookups. Unfortunately it is not labeled as to which side to put the drain hose. Is there an easy way to tell?

No. I would just take a chance and knock one of them out. Its not going to hurt anything. The worst that happens is you have both holes open. My concern would be not to let the plastic that you knock out fall into the drain. This can cause some serious drainage problems. I would make a small hole with a knife in the center of the knockout and then grab onto it with a pair of needle nose pliers, then have someone hit the outer ring with a screwdriver and hammer. You can also cut the whole plug out with a sharp knife, but make sure you have a hold of the plug so it doesn't go down the drain. If you don't want both holes open, just make a cut in the plug, pry it up and look in with a flash light. You will be able to tell weather there is a drain connected or not.