Randy Sandberg on "Help, my site is down and it's not the host!"

Here's a good place to begin for backing up WordPress:

http://codex.wordpress.org/WordPress_Backups

As for where to find someone to combat your possible SPAMmer issues, I am not sure. Technically I know a guy but I believe WordPres.org forum rules look down on folks handing out recommendations like this. But let's just say I trust the guy's voice over at WordPress Plugins A to Z (see http://wppluginsatoz.com). ;-)

Hope this helps!