I am really sorry Tonya. Whatever time you and your family have together with your brother, I hope is pain free, filled with love and lasts longer than anyone dreamed it would.
By all means make sure he does the will ASAP. Here is a link you might find helpful for legal forms and end of life issues.
familycaregiversonline I would not advise you to rely on an online form as his final will, however any legal will is probably better than no will at all.