Blogs display around 5-10 recent entries on the main page and the older ones are hidden in the archives. Some blogging software support
"Categories" and "Related Posts" but Google Blogger users are not that lucky.

Surfers want information quickly so adding a search box to your blog or website can be a great tool that will enhance the user’s experience while browsing through your blog.

Gimikera Is In used to have a Google search box in the sidebar but since I couldn’t add META tags to my pages, it wasn’t very helpful in searching my blog.

I read this article from Digital Inspiration and it listed the HTML codes of search engines that you can install in your blog for free. I opted for the Technorati Searchlet since it even lists how long ago the entry was posted to my blog.