Buying A Bike

Hey everyone,

I plan to buy a bike very soon to fully enjoy the summer this year. I would like something of good quality, but i wouldn't like to ruin myself with it, so i was wondering what is the most important thing to look for when bying a bike?

Please help

I didn't find the right solution from the internet.

References:
http://www.airliners.net/forum/viewtopic.php?t=1047353
Motion graphics animation studio

Thanks