Privacy Settings for Your WordPress Blog
This WordPress option gives you three very simple choices, and the choice you make lets you determine how you want to deal with publicity on your blog. To access the privacy options for your blog, click the Reading link on the Settings menu. You can choose one of these three options in the Reading Settings page in the Site Visibility section (about midway down the page):
Allow Search Engines to Index This Site: Select this radio button if you want to freely allow search engines to visit your blog and include its content in their search directories.
Discourage Search Engines from Indexing This Site: Select this radio button if you don’t want search engines to visit and include your site in their directories. This option is helpful if you want normal (read: human) visitors but don’t want the publicity that search engines provide.
I Would Like my Site to Be Private, Visible Only to Users I Choose: Select this radio button if you want to make your blog available only to the people you choose. This option keeps your blog completely private and away from prying eyes — except for those users you allow.
When you select and save this option, WordPress.com provides a form in which you can enter the WordPress.com usernames for the people you want to invite to view your private blog. (With WordPress.com, you can add up to 35 users at no cost; you can pay an annual fee to add more.)
When you finish making your decision, be sure to click the Save Changes button to have the changes take effect.