Hello bloggers, I have a client that wants to set up a blog. We typically just do ecommerce sites and I am looking for some suggestions on the best to use. I would like some turn key soft with these options:

1.100% W3C Compliant
2.Can Display Adsense
3.Google Friendly URLS
4.No duplicate URLs in navigation
5.Easy to use

Any good suggestions?
you advise will be appreciated

I think wordpress will do all them nicely for you. My blog uses it and it is certainly performing well in all of the above.

Joomla with OpenSEF and sitemap. OpenSEF can also export xml needed for google crawlers.

For blog WordPress (http://wordpress.org) is the best thing it is meant for that only and it will meet all the requirements of yours, joomla will not fit in as it is so much more than a blog.