Restore from backup.
For anything else, create a disk image so you can go back and try again. Optimize table may work depending on what's wrong (such as secondary index corruption).
Other than these two options, I'm guessing google, self education and most likely a lot of time is the only other answer. If using the last backup isn't an option and google isn't enough, I'd also advice you to post on mysql forums and stack overflow. It will increase your chances of finding someone with extensive knowledge and previous experience in the area.
It's possible there's someone here that can help as well. Just thought I'd give what little advice I can as soon as possible. Last backup gets old quickly.
