First thing that you must decide up on the url is to choose between http://www. vs http:// reason you should do that is to avoid canonical issues and sometimes it leads to two of your pages being indexed with same content which is not advisable and may lead to problems in rankings, in order to set your preference you have an option in your Google webmaster tools to do that, just go to settings under site configuration where you can change the preferred url.

Also you need to change your url in the admin panel of your blog. Just look for general option under settings and set your blog url and wordpress url pointing to your preference, if you want your url with www then enter it as http://www.YOURDOMAINNAME.com or if you prefer non www version of url then it to http://YOURDOMAINNAME.com check out the picture below on what I have set for my domain.

So this is just a basic step next we need to change the way your url is actually displayed so in order to achieve that go to permalinks section under settings and choose the custom option and enter this code there /%category%/%postname%-%post_id%/

I use this code but you are free to alter it the way you need but many top SEO experts use this structure and I prefer this structure myself and it adds little value to your over all SEO efforts.

So if your blog is on for a while and you have changed your permalink structure then you will be needing this redirection plugin which will help you to redirect your old urls to the new ones. Donwload it here

So that concludes our tutorial for optimizing your blog url to boost the SEO value of your wordpress blog.