best seo friendly url structure :
One of the most basic search engine optimization techniques is in using SEO-friendly URL structures. A good structure can help the indexation process of your website, but, unfortunately, there are plenty of websites that use incorrect, suboptimal URLs. In this article we take a look at the various elements of a URL and how we can create a structure that will help us rank as highly as possible.
Mind File Extensions
URLs that end in .html are favored by search engines. There are exceptions to this so make sure that you know your system well and that it’s friendly with search engine requirements.
If you still have certain doubts about your URL, go to a resource like seomoz.com There are spam detection tools that will help weed out things like spam words, and give you tips on hyphens, sub domain depth, domain length and digits. Again, all of this information is freely available online.
Hyphen vs. Underscores
The websites that contain an underscore in their URL are starting to become scarcer. The general belief now is that a user who is doing a Google search for “blue widget” will get better results from http://www.blue.com/blue-widget thanhttp://www.blue.com/blue_widget. Times change, and these protocols change as well.
Re-writing Your URLs
Lots of URLs that used to contain characters like &, +, =, _, $ and % are being overhauled to include more user- and search engine-friendly forward-slashes. This can get tricky, but there are plenty of tools out there to help facilitate this. Some are free open-source tools, and some are fee-based. The technical term is a “URL Mod-Rewrite” and this can easily be done via the .htaccess file on most servers.