If you post an articel to your blog it will displayed on a main page, if you have a long post content, your blog will opened more long time. But it can be tricked with a script to short your post or only abstraction post will dispaled on a main page, and the full post will replaced by "Read More" link. Here's the trick to create "Readmore"
1. You have to Login to blogger, then chose Layouts --> Edit HTML
2. Click on "Expand Widgets Template" checkbox.
3. Find the code below in your HTML Codes. ( the short way to find is by copy the code below then press "Ctrl + F" then paste in the box)
<div class='post-header-line-1'/>
<div class='post-body'>
or
<div class='post-header-line-1'/>
<div class='post-body entry-content'>
4. If you have found it, put the code below under the above code.
<b:if cond='data:blog.pageType == "item"'>
<style>.fullpost{display:inline;}</style>
<p><data:post.body/></p>
<b:else/>
<style>.fullpost{display:none;}</style>
5. Under the code, you will find code like this <p><data:post.body/></p> you have to put the code below under it.
<a expr:href='data:post.url'>Read More......</a>
</b:if>
6. You can change the "Read More" text with other.
7. Save your job.
8. Go to Setting --> Formatting Tab menu
9. At the lower page you will found "text area" box beside text "Post Template"
10. Put the code below to the box
<span class="fullpost">
</span>
11. Then click Save the setting.
12. If you want to post, put your short post or description above this code <span class="fullpost">, and the next or full post put between <span class="fullpost"> and </span> code.
source:http://trick-blog.blogspot.com