In reply to TN:
these steep hills you are doing are they on road or off road?
good suggestions (some already meantioned i know) are:
clips and straps or QR pedals (imagine pedaling in circles... not up and down)
the top roadies seem to recomend spinning the pedals at about 90rpm (count ur right leg coming up 15 times in 10secs) offroad i tend to pedal a bit slower as i find it aids balance.
if off road, try pushing your bum towards the back of the saddle a bit, and bending your elbows in and down to move your shoulders forward, loosen ur grip on the bars a touch.
but the things that make the biggest difference for me are actually mind tricks.
first off don't watch muz to closely, concentrate on you.
try and control your breathing if you can keep that as long deep breaths you'll start to feel better sooner.
break the hill into sections and ride each section, forget about the rest of the hill until you reach the next section (in your head you're going "yay, i did that bit, now lets do this next wee section") before you know it the hill will be gone
when you reach the top of the hill, don't sit up on your bike and go "phew glad thats over", the tip is to keep riding over the top of the hill changing into a higher gear and pedal for about 10 - 15 secs before you sit up. (that was a tip from when i used to race and it really works) otherwise your mind and body treats the top of the hill as the end of the climb where as the end of the climb isn't until you are back up to speed again
and finally, make sure you are taking on enough fluid. i know this might sound ecky but if you sweat a lot consider getting an isotonic drink for your bottle. isostar / high5 are both good. and do some stretchs when you've finished.
keep at it kid, cycling is great fun and even better when ur fit