Do I have to have a Gmail Account to log in to Blogger?
The answer to this much asked question, is NO.
All you need is a Google Account, which you can create using any legitimate email account and password.
So, what is a Google Account?
According to Wikipedia, "A Google Account is a user account which provides access to Google-owned services such as Blogger, YouTube, and Google Groups. A Google Account can be identified either by the username (usually the associated email address) or by their unique permanent ID."
Blogger describes a Google Account in this way; "A Google Account functions as a single Google login, made up of an email address and password of your choosing. It gives you access to various Google services, including AdWords, Google Groups, Google Alerts, Froogle Shopping List, Personalized Search, your Personalized Homepage, and Google Answers. If you've used any of these services before, you already have a Google Account."
Having a Gmail account is great because it has an in-built Google Account, and many other benefits.
Everything else, you may need to know, about getting started, can be found on this Blogger Help page.