SSX Blur has a steep learning curve. You will be disappointed if you expect to pick it up and master it in a few hours. However, if you are patient you will find SSX Blur to be a rewarding and extremely fun experience. Here are a few tips to get you started when you first hit the slopes:
Master the Tutorials
Even though there doesn't appear to be any rewards for completing all the tutorials, be sure to spend some time with them. Most of them will be straight-forward, but you may find some of them a bit maddening. Just keep going and do the best you can. You can practice drawing the ubertricks by clicking while in the tutorial menu. Also keep in mind that grabs are performed by holding and twisting the nunchuk left or right.
Jump Using 
The tutorials suggest flicking the nunchuk up to jump. I recommend using to jump while getting used to the controls (hold to crouch leading up to an edge, then release to jump). You will be doing quite a bit of gyrations with the controllers, so start simple, then learn the "flick jump" later.
Disable the Nunchuk Motion Turning Control
Go to Options, and fine tune your controller by placing all left-right control with the nunchuk stick. This will disable the left-right motion on the nunchuk, making turning, and events like slalom much easier. Once you get better, come back and re-adjust this option to experience the motion-sensing goodness of the nunchuk.
/ Will Help You Land
If you are coming off a big jump and are not sure whether you will be making a smooth landing, mash on or before landing. Your character will re-position him/herself and almost always land correctly. Doing this will shave points off of your ubertricks, but this is a good technique to learn to get used to landing correctly.
If you think of this game as a simulation, you will be up-tight and try to be too perfect in your movements. Just relax, let loose and remember that this is a very crazy, over-the-top, fun game. You may find that disabling the music and DJ audio while you are getting used to the controls is very helpful. But be sure to at least turn the music back on later—it enhances the experience!
Choose A Character According To Your Skill
Make sure you are using a character that plays to your strengths. For example, if you are good at speed events, use Elise—if you like edge and control, use Moby. Some parts of the slopes will feel impossible at first, and in reality, they will be due to your lack of experience and your characters low ability attributes. Just keep building up your character's attributes until he/she is ready for those difficult events.
Character Upgrades Help
Once you start feeling more comfortable on the mountain, don't knock yourself out trying to get a gold medal in every event. Getting a Silver or Bronze (red?) will usually be enough for progressing. Keep plugging away doing challenges and events and eventually your character's abilities will be upgraded. Once your character is upgraded, go back and go for the top spot!
These tips will get you going, and once you've unlocked all the peaks and have upgraded your character, you can really begin to master the controls!