First, it is usually a good idea to create a regular user account and work with that regular user account on a day-to-day basis. This will prevent you from doing something that you will SERIOUSLY regret
Next, if you want to recursively delete a directory structure, type rm -rf <directory> .
BEFORE YOU DO THIS, type pwd and ls to make sure that (a) you are in the directory you want to be in and (b) that the directory that you are wanting to delete is there. The reason for this is that rm -rf executed as root WILL ERASE IMPORTANT FILES IF YOU ARE NOT CAREFUL. (i.e., if executed from the / directory, will delete all files on linux system).
If the directory listing done under a regular 'ls -l' shows no files, try doing an ls -ld .* (shows all the dot files under that structure w/o listing the directory above you) .
Check out the UNIX command reference on TechRepublic - I'm not sure what the link is, but it lists several frequently-used commands for UNIX and LINUX.