How to create "read more" on your blog

how Can i create expandable post summaries?. but do not jump on Cobain, I've tried several times but failed.
and i follow the  blogger's help, especially on the style / css.
how:
login to blogger.com, select the blog that you want to edit,click the link and then go to edit layout html to be ngedit template in its entirety, you must check / mark / expand widget templates enable Please enter the following code before the tag or just after the code } ]]>; like this:
 code in your template and add the following code right below it:   read more ..    that was interrupted, every time you post, click on the post where you want to read more papers .. appear, and type remaining posts until the end . add this code, when you post must be in edit mode not compose html