Hi,
To redirect a directory
redirect 301 /adir
http://www.mysite.com/bdir/
To redirect abc.html in adir subdirectory to def.html in same subdirectory
redirect 301 /adir/abc.html
http://www.mysite.com/adir/def.html
To redirect entire site from
http://mysite.com to
http://www.mysite.com
RewriteEngine On
RewriteCond %{HTTP_HOST} ^mysite.com
RewriteRule (.*) http://www.mysite.com/$1 [R=301,L]