Guide to Joining Google Groups
In your internet browser open https://www.google.com which will give you a page similar to this.
Click on Sign In which will open this window
If you already have a Google e-mail address and password enter these in the boxes on the right.
If not click on create one for free which will open this window
Follow the instructions on the screen and click the I accept, Create my account button at the bottom.
If everything is okay you will receive a message saying that you have been sent an e-mail to your previous non-Google address. Open that e-mail and click on the link that Google sent you and your Google e-mail address will be activated.
To join any of the Google Groups you must first sign in with your own details and then click on the invitation to join link and you will be taken straight into that Group.