There is a lot of video, tips and technic to improve your ground fighting skills!
http://trainfightwin.com/index.php?option=com_parainvitepro&task=namecard&userid=251&Itemid=153
that's my fav. i just found one called submissions101.com
I don't like to fight the ground. It hurts my hand. I usually use a shovel if I want to attack the ground but most of the time I just walk all over it.