"A description for this result is not available because of this site's robots.txt – learn more" i am new on wordpress cms, so when i search on goolge shwoing this text , why not showing meta description? how can i add a Robots.txt file?
Better to install any seo plugin such as yoast and add meta description there for each page . Following link will help you for robot.txt config : http://www.seomoz.org/learn-seo/robotstxt Good Luck
yes ,you have to wait 24-144 hours for search engines .Plus, submit your sitemap manually to google along with signup in google webmaster tools.
If the file robots.txt is involved then no plugin will help you. The page is probably being blocked by the website owner (unless Google made an error). If that is your website, make sure that WP doesn't prevent bots from indexing it (Settings → Reading → Search Engine Visibility). You can view the file by opening example.com/robots.txt in your browser.
I think that it is fine. Although I am not sure why do you want to block these folders (Google is "smart" enough to not try index them, besides there are usually no links pointing to these locations).