The quickest fix to get you going again would be to move your work files to your Shared folder. That way any admin account can use them.
Make sure you've downloaded all updates from System Preferences/Software Update. What OS X are you running? 10.4 or 10.5?
Once you have some time, I'd recommend first doing a repair permissions (apps/utilities/disk utility/repair permissions) and then if that doesn't work get your os x install disk, boot up with it (do NOT reinstall OS X), and run Disk Repair from the File Menu.
If those things don't work, you may have some corrupted preference files. Search for each app name, Illustrator, Photoshop, etc. and move the .pref and .plist files you find to the trash. This will reset your apps to default.
Are you using font management software?