This is an instructable with a video tutorial that teaches how to install GPG4win and FireGPG on your computer in order to send and receive encrypted e-mail through Gmail.
I made this tutorial to teach friends and colleagues how to setup their Gmail for encryption.
Encryption is very important because e-mails are very unsecure. An e-mail is equivalent to a postcard, ANYBODY CAN READ IT.
So if you want to send personal and private information, you better encrypt.
By the way, you need windows in order to run the programs mentioned here, if you have a mac then go to this instructable.