Currently Being ModeratedDec 5, 2012 6:57 AM (in response to RikaW)
Easiest is to connect an external hard drive that is at least as large as the space being used on your hard drive and then use Time Machine or a program like Carbon Copy Cloner to make a backup of your data.
You don't say which model of 2009 MacBook you have - there were three - and Apple dropped FireWire from the MacBook that year for the last model. Be sure you get a hard drive that will work with the connections you have.
Note that having backups is important even if you are not sending it in for repair. You should develop a habit of keeping your data backed up at all times. Remember there are two kinds of hard drives - those that have failed and those that are going to fail. The only question is when. Backing up your data constantly is the only way to keep it safe.
Best of luck.