I have a project in SE at college and me and my group have to develop a web app which will allow them to recruit students for different projects..etc. In other words the end result it should be some sort of pop-up type advertisement, maybe an applet which interface message can be customized before placing on the website. Once the add is placed on the website, the visitors to the site will be able to read the pop-up type advertisement and if they choose to participate, all they will need to do is to click on and complete an enrolment questionnaire, which will store their details...etc into a database. The data should be viewable and editable by the end user.
In my opinion the best approach is to create a Java applet easily customizable HTML/CSS interface. To store applet data in a database on the web server, SQL would be the easiest solution, while to read and view data use SQL commands from Java to get results as well use Java to display or manipulate that data.