Hi mvang,
I looked at your site, I assume you want the readmore on the three featured articles at the bottom of the page? Is that correct? or are you going to add an extension like the slider on the sample page?
If those are custom html modules, you'll need to manually insert a readmore link like any other link.
If those are articles, then you use the readmore link button in the editor to create the readmore link when you create the article.
In the sample site you sent us the only readmore links are on the product slider at the bottom of the page. Putting readmore links there is most likely part of the configuration for the module and/or plugin that creates the slider.
If you're going to use an extension, we might be able to help you if we knew what the extension was.
Let us know if that answers the question. It's still not clear to me exactly what you want to do.
Cheers,
Ed