Google has updated their Webmaster Guidelines, mainly added more examples and going a little more in-depth on specific topics.

None of these updates are groundbreaking but for any SEO who does not keep up with industry news and updates on a regular basis, here are some of the important ones I picked out:

• Rich Snippet guidelines have been added
• Buying or selling links that pass Page Rank.  This includes the exchanging of money for links, posts that contain links; exchanging goods or services for links; or sending someone a "free" product in exchange for them writing about it and including a link.
• Building "partner pages" exclusively for exchanging links is a no-no
• Using automated programs or services to build links is a no-no
• Text advertisements that pass Page Rank is forbidden
• As are links inserted into articles with little logic

The full page on Webmaster Guides referring to Link Schemes can be found here: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=66356