Thanks to everyone for the help. To respond to some of the specific suggestions:
I immediately reset my IP when I noticed the attacks. I have had SSH 1 disabled for quite some time. I checked the sshd config file and discovered that root access was enabled. That's fixed now. I've installed logcheck to notify of any unusual events each hour. So now I only have to glance at the logcheck emails which will make a huge difference. Thanks!
