Here is the steps to do that.
1. Login your Google account. Take the webmaster tools, type your URL in the given area and click add site

Then Google will ask you for verification. Click verify your site.

Select the method for verification - select add a meta tag

You'll get a code to insert in your blog copy that code and goto your blog

2. Sign in your blog, click on edit HTML [customize-> edit HTML]

Then

Insert the code in the first "head" section of the page, before the first "body" section.as shown

Save it. Then go back to the webmaster page and click verify

The page will get verified and you'll get this

Then you have to add a sitemap for your blog. Goto Dashboard of webmaster tools.
3. Dashboard

For this you have to create a RSS feed for your blog. Goto feedburner.com get an account and enter ur blogs address and create feed

Note down the feed address. And activate the feed. Use RSS feed

RSS feed

Then go to your blog goto customize->settings- >sitefeed

Click on site feed
Allow blog feeds to “full” and enter the feed address you taken down from feed burner ,in Post Feed Redirect URL field

save your changes
4. Go back to webmaster tools page and click on add sitemap

Chose the option Add general web sitemap

in my sitemap url field enter “ rss.xml?max-results=500&start-index=1”

Click Add general web sitemap, You will get this

its over google may take 12hours to days to crawl ur blog wait patiently. It may even take days to show your contents in index wait oki. Its over. Enjoy