Shorter Post In Index Page?

I wanna have shorter posts in index page.
Normally it is showing the whole post in index page which is stretching the page alot so i wanna have shorter post in index and then the text after each post “Read the rest of this entry” for reading whole post.
So can anybody helps me in doing this.
You can see the following image this is what i wanna do.
http://i22.tinypic.com/152yutt.jpg