For a brand new application, is it better to use WPF over Windows Forms? I used Windows Forms before but not much WPF. As far as I know, WPF is the successor to Windows Form
In your case, WPF makes sense. For me, it's an application by application choice because there are a lot of things you can do really well in Windows Forms (like rapid development of business applications). I'm using WPF to write a nice GUI for a media center application (personal project for a media console on my 50-inch plasma screen).
However, if I'm writing a data entry and display application, I typically go with Windows Forms for speed of development. The XAML editor is better in Visual Studio 2010 but still has a way to go. Without a reference there's no IntelliSense help on a lot of the property attributes so it's impossible to know what goes in them (which is where I spend a lot of my time trying to find those values, either through a book or examples on the web). That said, if you do WPF write, you can make some very compelling user interfaces.