Can somebody explain Canonical tags and the technical elements of SEO?

[Buzzwords]

Newbie here,and learning fast. But... I can't help but feel the technical elements of SEO (i.e. canonical tags, javascript amongst others) are holding me back. My knowledge of  programming and coding is basic at best. Do I have to have an understanding of this to get ahead in SEO or is it simply a case of reading some more and knowing the techniques? What percentage of SEO is technical (e.g. html coding etc...) Thanks in advance. N.

p.s. could someone explain what canonical tags are?

[icecarats]

There are many, many, great frontpage SEOMoz articles that explain a lot of this stuff. In the abstract I would say that 'strategic' SEO (e.g. overall site structure and planning) does require a grounding in technical issues but that 'tactical' SEO (e.g. per keyword or category content creation) doesn't necessarily, as long as there is a clear understanding of what is to be accomplished and how.

Here's a good article from the Learn SEO series on this site:

http://www.seomoz.org/learn-seo/canonicalization

(The whole Learn SEO section is pretty good)

The short answer is, canonical tags tell search engines what you want the 'real' URL for any set page to be when presenting it as a search result. Consider these URLs, which all theoretically go to the same place:

mysite.com

www.mysite.com

www.mysite.com/

mysite.com/default.aspx

www.mysite.com/index.html

If search engines treated all of these as 'different' pages, it means that your 'link weight'' or relevance for them would be split 4 times, depending on how many other people linked to them, how you link to them internally, how your sitemap references them, etc. But you don't want that; you want 'one' default page for your site. The canonical tag lets you explicitly specify which of the above should be considered the 'canonical', or original, page.

This has a variety of applications, but these are the most important:

• Controlling capitalization. Is there a difference between Default.aspx and default.aspx? It's unlikely, but canonicalization can take care of this

• Reducing search engine confusion for identical pages, as above.

• Reducing querystring over-indexing of duplicate content. If you can have over 100 iterations of SearchResults.aspx?Start=0&End=100&Sort=Asc, SearchResults.aspx?Start=10&End=110&Sort=Desc, etc. etc. you can canonical them to the original, plain, SearchResults.aspx to help avoid duplicate penalties.

I'm sure there's more, but I'm just writing this off the top of my head.

[Dr-Pete]

It's a bit of a read, but I discuss a lot of on-page tag/tactics in this post, inspired by Panda:

http://www.seomoz.org/blog/duplicate-content-in-a-post-panda-world

If you're launching a very large site (like an e-commerce site) with 1000s of products, then a deep knowledge of on-page SEO can be critical. For most sites, though, that grow organically, you can learn as you go. As you start to track your own content and rankings, you'll begin to see what works and what doesn't.

Early on in a site's life, a lot of on-page really just comes down to solid keyword research, a sensible site architecture/structure (navigation and internal links), controlling duplicate URLs, and writing decent TITLE tags. That'll take you a long way in the beginning.