Yes and no, depending on how much you will be using Google Groups. No, if you will not need to sign in to Google Groups for example to create your own groups and if you don't need to change your Google Groups settings (for example your name and email delivery settings). Yes, if you want to sign in to Google Groups to be able to discuss by also using the Google Groups web interface and if you want to create and manage your own groups and if you want to change your Google Groups settings. You can create a Google account associated with your email address here: https://www.google.com/accounts/NewAccount