How do authors login?

I recently created a blog, and I want a guy in another state to login and blog. I created an “author” account for him, and gave him a “level 2” (which, after reading online, seemed to be right?). I am wondering 1.) if this is the right “level” for someone who I want to let in and make posts, but not to change any settings, and 2.) how to let him LOGIN. I tried loggin in with his first and last name, and password that I set, but that did not work. Thanks..