Strong Passwords and reasonable password change frequency will definitely help. How ever to prevent hackers from intruding to your boxes, use firewall... there are many available in the market... Always remember not to send passwords, account information, credit card numbers through the email or SMS.

Now a days we have Phising Scam, always look for a encyrption (Will Look like a Lock) on the right hand corner of the screen. Remember no banks or agencies will ask you to enter your account information... Hope this helps.