We don't have an empty project, but we have several populated ones. Do an ls */jbossbuild.xml in jboss-head to see several examples. At this point, the kernel module is probably the best example of what your directory structure and jbossbuild.xml should look like.
I'll take a crack at a canonical component source structure:
<component/module root> build.xml (component definition) .classpath, .project docs src bin (*.sh, *.bat) etc (default.mf) main test (unit tests) resources dtd test properties (*.properties in org/jboss/**)