To simply rename a file, type "rename [filename] [newfilename]". The file should now have a new name.
To move a file located in your "www" directory to another directory, type "rename [filename] [new/path/to/filename]". The file should now be located in the directory you specified.
Example: rename test.html mydir/test.html (where "mydir" is a sub-directory of the directory test.html is located in)
You may also move and rename files at the same time.
Example: rename test.html mydir/misc.html (where "mydir" is a sub-directory of the directory test.html is located in)