Here are some things that you should be doing regularly to improve the life of your bike and to make rides less problematic.

Before every ride:

1. Check the tires for damage on the tread and sidewalls
2. Make sure the brakes are functioning properly
   
3. Check brake pads for excessive wear
4. Check for loose parts (bounce the bike lightly and listen carefully)
   
5. Do you have a flat tire repair kit, cell phone, and personal identification
   

Ever few hundred miles:

1. Degrease/lube chain
2. Check chain stretch and gear tooth wear.
   
3. Excessive play in the bearings (hubs, bottom bracket, headset, pedals)
   

After a crash, check for hairline cracks in the frame and components, and replace your helmet.