iCloud prompts me to create a free @me.com email address to turn on Notes sync
The way that Apple handles notes on the iOS devices is that really they are just specially formatted email messages being sent to yourself from yourself. This was a bit more obvious in earlier versions of OS X as the notes you would write would appear in the apple email client Mail.app.

If you want to use you iCloud account to sync your notes then yes apple forces you to create a free iCloud.com (used to be me.com) email address which is really not a bad idea, but for someone who already has a gmail account it certainly is not necessary.

if you would rather have your notes sync by way of your gmail account you will need to open the settings app on you iOS device(s) then tap on "mail, contacts, calendars" and add your gmail account there. You will then have the option to turn on or off several services like email, contacts, calendars, and notes. in fact you can turn on nothing but notes should you desire.

it wil also be a good idea to visit Settings > Notes on your iOS devices and choose the account you wish to be your default note creation account to avoid any future confusion.

If you are setting up notes on an OS X computer and need help try using this online guide that apple provides. it covers how to set up mail and other services on a number of different systems.

http://www.apple.com/support/macosx/mailassistant/