Installing a second blog which I can update etc from the same dashboard

Is this possible?

I’m with bluehost, I’ve had a good look at the Installing Multiple Blogs help section but it doesn’t help me a lot. So far all I can do is have a second blog on my domain that uses a different password, and even then it seemed to mess up my first blog.

What is a step by step way to create a situation where I log in and can switch between my two blogs easily without needing two usernames/passwords/dashboards