First- spend the money and time to make your sled comfortable to ride standing, very important to be comfortable and confident. find the "sweet spot" on the sled - that is the point for me that when your bouncing the sled it rocks for and aft, and there is a natural pivot point, put your feet slightly behind it and get your bars just in front of it. this will allow the sled to "dance" under you, while you move very little.
second get to know your machine - play in a meadow and throw it around under power. Even experienced riders will borrow a friends ride to try it out and fall on their side and "lose it" everyone laughs - no big deal.
third/4th - steer with your feet and throttle not your skis, only use your skis to put corrections into a turn. Suprizingly try turning your skis the opposite direction that you want to turn (countersteer). There is a real reason this works it has to do with fall lines and thrust vectors of your sled, Just kindof think as the back half of your skis as rudders on a boat,
most manuevers on a sled require timing more than effort (although there is still penty of effort going on), the throttle is your friend in most situations, get the track to spin under the sled it creats a stabilizing trench under the sled and the track removing the snow from under itself will allow small inputs with your feet or on the bars to change your direction and or level the sled.
any time you want to try a manuever (sidhilling, tight turning like a jet ski, S turns etc-- -- -- START VERY SLOWLY- meaning creep up to the point you want to start, then hit the throttle (now here is the tricky part, you have to time your input to the sled just as the track starts spinning under your feet, if you stomp or pull too quickly nothing really happens, do it too late and you rocket off in the direction you were pointed.
AGAIN start SLOW SLOW SLOW. 1-2 mph or so, get ready, pin it, wait till you feel the sled drop as it starts to trench or you feel the TRACK SPIN (not the engine reving) stomp your feet, pull your bars.
You will fall off and you will go too fast, then let off and get high sided, so do it in a safe place- If your going faster than 10-15 mph, stop you blew it try again, leave the fast sidehilling for when you have experience (high siding at 30-40 sucks) remember SLOW SLOW SLOW is the key. watch how slow the other riders are going when they do it.
if someone laughs just aske them for help either they will shut up for fear of doing the same and looking like an a$$, or help you out with their tips.
remember go slow then get that track spinning, when it gets stabilized then work the throttle on/off to keep where you want to go and and the speed you want to go.
good luck, if your in Utah look me up!
spomey