Cannot say exactly what to do with so little info about your project, but usually steps are:
1. Creating server runtime and server instance based on it
2. Importing your projects in eclipse (there are many ways to do that and it depends on what kind of projects you have)
3. Deploying to the server instance using "Add and Remove..." action on serever instance or using DnD from Package Explorer to server instance or even JBoss Archives Component
4. Install break points and start Server in Debug mode using Start in Debug Mode button
5. Trigger start fro your application (the way to do that dependes on what kind of application you have)
Aditional info is here http://docs.jboss.org/tools/latest/en/as/html/quick_start.html