Apparently, if you want to be an educator in Scotland, you need to know something about blogs. If you don't, you fail an exam! For that purpose, the Scottish Qualifications Authority has put together a really nice primer on blogs and blogging on a Wiki. It should be useful for everyone, not just Scottish teachers. Check it out here.
It is only a tad little bit out-of-date which should not be a problem for newbies. Also, it contains the '10 Rules' by Jakob Neilsen, that were viciously eviscerated by bloggers who actually know something about the medium (use Technorati Search to find those posts form last year).