How long has it been since you changed your passwords? For most people, this is a set it and forget it (well not really forget it but never change it) task. It is important to change your passwords (to email accounts, online bill paying and online banking accounts, other online accounts such as EBay and Pay Pal, for computer and building access, etc.) as well as your PIN numbers (to your voice mail, answering machine, bank and credit cards, etc) on a fairly regular basis--at least once a year or more often if you suspect your passwords may have been hacked.
To create a strong password, consider making it a longer word, add some numbers and special characters, and never use an easy to guess name or number (ie: birthdays, kids names, etc). Obviously don't write the password down anywhere--commit it to memory--and most importantly, don't forget it!