I have this idea for a small-medium web application that I would like to build, probably with a combination of Velocity and Spring MVC. My problem is that I have never dealt with issues such as user registration, or with design issues such as CSS, layout, etc.
I'm pretty confident I can build the application/domain layer of this application, but how should I get started on the user interface side of it? Are there any resources on how to manage users, and on how to, well, make the app look good? I don't necessarily need references to the classics on user interaction design, but rather pointers to how to implement these ideas with the most popular frameworks.