All in one SEO Pack is a wordpress plugin that will give you the ability to set Meta Data for your site, Posts, Pages including Title Description and tags for any or all of them you can even exclude certain pages or posts in another word it will give you a full control over the SEO meta data of your site.
at the time of writing this post it has 7,725,652 downloads.
Using All in one SEO plugin will make the task of optimising a wordpress blog as easy as 1,2,3 just install, activate and then enable it and it will do all the work for you. You can even prevent duplicate content with this which is a common problem with WordPress. all you have to do is to set tags, archives and categories to have a no-index which is on the option page of the plugin and the plugin will take care of the rest.