Warning! It is being reported that Gmail accounts are currently easily hackable:
Hacking Gmail accounts with password reset system vulnerability | The Hacker News - Security Blog
It is not known yet if this is a confirmed vulnerability, or if 2-step verification can prevent it, but it can't hurt to enable 2-step login verification now on your account if you have not already:
http://www.emailquestions.com/gmail/3509-setup-gmail-2-step-verification.html
If your account has already been hacked please see this guide:
http://www.emailquestions.com/gmail/1111-recover-lost-gmail-password.html
Hacking Gmail accounts with password reset system vulnerability | The Hacker News - Security Blog
It is not known yet if this is a confirmed vulnerability, or if 2-step verification can prevent it, but it can't hurt to enable 2-step login verification now on your account if you have not already:
http://www.emailquestions.com/gmail/3509-setup-gmail-2-step-verification.html
If your account has already been hacked please see this guide:
http://www.emailquestions.com/gmail/1111-recover-lost-gmail-password.html