It is the time to take precautions about getting hacked.In the last weekend,i think you heard that news "5 Million G-mail Accounts are Hacked and Published hacked details".
When you are creating Gmail they need your phone number for security verification by texting a 6 Digit Code to the Given Phone Number or a voice call to that number.This will give maximum security to your account.
Click here >>>>>2-Step Verification
You can setup the 2 step verification from your tablet or mobile but i think your PC is more better to do this.Go to Google Security Settings and click on two step verification.Then type your mobile number and choose a way to get verification code,Text Message or Voice Call.Then Click on 'Send Code'
Then Click Verify.
Then Verify your Machine whether it is computer or other devices.Then you can add devices in to it where the g-mail is using.It will alert you when your g-mail signed in any devices.
I think this is the better way to make security on your email.Ensure your security now....!