I think it is important between position and turning technique. I am going to focus on the position you want to have while going straight, without actively breaking, accelerating or turning - i.e. a "neutral" or "basic" position.
First of all I agree with @Gabriel C. that you should have an active stance. For me this means having body tension, but not being stiff as well as being able to bend and/or straighten your knees when necessary.
Second, it is important to have your weight to the front (when skiing on prepared piste). The further your weight is to the front, the more control you have on how your skis behave. You can experience this yourself: try leaning back, and you will see how your skis start to flutter. Lean front, and they will be much more steady. I have seen a lot of beginners that lean to far back, especially when they start to panic. This makes the situation worse, because the skis react worse and worse to their attempts to control them. It might need some confidence to lean forward in a way that would cause you to fall without skis, but just try it out!
To achieve the combination of these, it makes sense to bend your knees a little bit (allows you to react to bumps and the like) as well as your hips (allows you to lean forward so you get your weight to the front and control over your skis). It is important not to bend your knees too much though - this would cause your backside to be very low and to the back and can be a difficult position to recover from, depending on the strength of your thighs.
See this illustration I shamelessly stole from this site you might want to check out as well:
Furthermore (assuming you use carving skis), leaning slightly uphill and putting more weight on the uphill borders of your skis will straighten your course and give you more speed. For turning, I would just push my downhill ski slightly forward and change weight to the downhill edge.
I am unsure if I have more weight on one of the skis in the "neutral" position, but I think I distribute it quite evenly.