How are super delegates picked?

http://www.nowpublic.com/culture/okay-so-what-super-delegate

For starters, Super delegates are current and former leaders in the Democratic Party with voting power, existing only in the Democratic Party. They are not to be confused with the regular delegate count, referred to as pledged delegates, delegates which are apportioned by statewide votes acquired by a candidate, with approximately 25% of the delegates awarded in this manner. The rest are meted out by sub divisions, mostly through congressional districts.

This year, after the tally, there are 796 Super delegatesthat will be involved in the process at the 2008 Democratic Convention. Their votes will become crucial if there isn't a clear indicator of a Democratic nominee after all of the Presidential primaries.