"Do I have to sign up to use the searches and view the details of listings like on some sites?"
NO! But opening an account will open up many conveniences for you.
So, read on and learn about it. Here's What Will Happen...
After you set up an account, each time you log into it, your own personal Menu Bar will appear at the top of each website page. You've turned the entire Your Own Broker website into Your Own Website.
As you use your website, you can save searches so that you don't have to define them again. You can order periodic reports of new listings matching your Searches. You can designate particular homes you've found as Favorites. And you can define, organize and print out driving tours to see outsides and neighborhoods of selected homes.
From your Menu Bar, you can use your saved Searches, look at your Favorites, design TourBooks, and browse the Reports that have been sent to you.