You may want to add tabs/menus on top of your blogger.
Actually they are nothing but a web page that you can make a link. For my case, I use label to get the posts with the label. For example, with the Python tab, I link http://prosseek.blogspot.com/search/label/python, and so on.
Then you can visit blogger.com to select your blogs.
Click Pages to add the page you want. Don't forget to set the "Show pages as" to "Top tabs".
You can change the configuration