First off, when you are first starting out, I recommend using a handheld meter and using it to get to know your camera. I used a meter for about my first year and then I learned to judge it by eye. I shoot with a Canon 5D and my camera is almost a full stop off. So, I meter in camera and then adjust, but every camera is different. (I have a backup 30D and it is only 1/2 stop off)
Also, you have to make sure you are metering for the right thing. I always meter for skin. A lot of people set their cameras on overall metering and your camera scans the entire frame and gives you an average meter, I have found it to be wrong 99% of the time.
There are times when I will meter for something other than skin, but 99% of the time that is what I meter and adjust to my taste. Mostly it takes time, patience, and practice.
HTH!