Matt Cutts, Google's official Search Engine Optimisation blogger, has been giving the SEO community do's and don't tips for 16 months now. Blogging daily the cumulative volume of knowledge and advice is impressive.

It is only on looking back that the value of Matt's advice becomes evident. Rather than trawl through thousands of Matt's blog entries, here are my top 10 favorite Google tips

1. Use user-friendly URLs, or human readable URLs, e.g. rose-flowers.html, blog entry here
2. Minimize the number of parameters in your URL - maximum 2 parameters
3. Use natural links as far as possible; linkers to your web should be citing or referencing you for a reason; links should be earned and given by choice.
4. Google penalizes bought links, Matt says the Google algorithm now identifies bought links, and considers them outside Google quality guidelines. High PageRank web sites that sell links widely have their links dampened such that their effetive pagerank is much reduced. blog entry here, here, and blog entry here
5. Use the “id=” named parameter in a URL with care , i.e. only for a session ID
6. Matt recommends using dashes to delimit URL words, rather than underscores
7. Use 301 redirects wherever multiple URL point to the same page Where several URLs, eg: www.enclick.com, enclick.com or www.enclick.com/index.html point to the same place, you should 301 redirect to the URL where you want all the PageRank concentrated. Alternatively, use google sitemap to help Google “canonicalizes” to the url you want to use. Canonicalization blog entry here
8. Google updates its index data continuously But, the toolbar backlinks and PageRank information is only refreshed every few months. blog entry here
9. If you use flash, offer an html version as well
10. Metadata still has value. Assign useful "title" and "description" tags and headings to every page.

Pretty obvious that Google is making progress towards its perfect citation model algorithm where only natural links and value-added references and citations are valued.