There are a ton of free weight and machine exercies that can help, and an hour on the weights can be enough, if you are busy all the time in that hour. If you are talking and waiting, your not exercising. Some rest between sets is needed but many people take way too long. Be setting up for the next emphasis area (i.e. Upper body, then legs, then abs etc...).
It also depends on what you are trying to develop for. Fast twitch (Big weights few reps few sets - strong weight lifter stuff) or slow twitch (endurance lower weight, tons of reps and many sets) muscle development. Check out some of the other stuff mentioned above you should be ok. But don't overlook a ton of other stuff that will help and do not require a Gym to do. Check Harold Harbs site for a lot of non gym stuff at:http://www.harbskisystems.com/dryland.htm
Then try and get your hands on a video I think is called "Fitness for Skiing." Almost the whole video is on balance, aerobic, and plyometric exercies. If you can get through these you will be doing great. Also find a basic aerobic/anerobic that you can do to build up your wind. Running, cycling, roller blading, step aerobics, swmining, are a few that come to mind.
Also, take some time to do some tumbing. Simple stuff. This gets your body use to moving in unsual directions.
I generally divide my year into blocks for the major things I like. Skiing & Cycling. I then put together a plan and follow it to peak at selected times during the year. December - Ski trip, Feb. Ski week, Spring, Ride to LA from San Francisco. Summer, The "Markleville Death Ride", Fall virtual ski.
You also have to feel your body. What is weak after a day of sking? Then you need to identify exercies that will work on that more. Plus you need to do stuff you don't like. Curles may look great but doing step arobics or plyometrics at high speed may be better for you. My personal hate is pushups. I do them every morning and night and hate all 30 of them each time.
The short answer is you will be spending your whole life learning your body and researching the best way to maintain it for the fitness goals you have.