Check the resources tab on this site and then drop down to the tricks section and weed through all of the idiots posting shit, and find a couple of decent guides on 360's... or my personal little guide, which i've learned from experience just a couple of weeks ago.
Make sure you practice spinning before you get to the snow. You will find you usually jump now with your hips, and not with your head. But, when you practice, make sure you rotate your head hard in the direction of your spin and let that pull your hips and your body around. Now... when you are ready to hit the jump... do it on a decent sized jump as it becomes twice as easy that way... i would recommend 25ft if you have the juevos. Before you hit it doing a 3..do some straight airs or some grabs...maybe some 1's if you can do them. Then... get ready and make sure you have enough speed to clear it.. because realisticly the reason you will get fucked up really bad is if you do not hit it with enough speed... if you make sure you can get to the landing .. it will be a little scarier.. but you will reap the benefits. Anywho... so ... you have enough speed and you are approaching the jump... make sure you have a wide stance as that will help to level off your spin... make sure you have a nice tight middle... i.e. your abs, not killer flexed, but i find that when they are flexed you will have much more success, ok.. also as you approach the lip have your arms on the opposite side of your body in which you will be spinning, so you can throw them with your spin to help your rotation...now you are hitting the jump... you need to make sure that you 1. get off the lip without starting your spin, and then 2. that you POP OFF THE LIP. If you start your spin before you get off the lip.. you will go corked, and you can't handle that yet, and you will fall hard, so make sure you get off of that lip before you start your spin. Ok once you are passed that you want to make sure you pop off the lip, and roughly when the tips of your skis are off the lip, POP and throw your head most importantly.. in the direction you want to spin, and keep looking in the direction of your spin, also as you are throwing your head, throw your arms in the same direction. So at this point you should be in your spin, then the most important part is to keep looking over your shoulder in the direction of your spin, because if you stop looking, you will stop spinning, but when you see the landing of the jump again.. look at it, and spot your landing... then your feet and body will follow as long as you stay focused on the landing...then touch your feet down and ski off with some steezeness like it was nothing.. and just keep progressing... that's all there is to it... also if you fall.. get right back up again... do some tricks that get you pumped, and then....get on that chair lift go back up and throw it again. If you commit you will get it...
See it, Pop It, Throw It, Stick It ...
hope that helps....
'OMG! That was the STEEZE! You just broke your face on that rail.'