Here's an entry.. This will show up on the main page. But not this stuff:

<lj-cut text="What you want the link to say on the page. Default will be Read More...">Images or text you don't want to show up in the first entry. Some people do this when they have an extra long entry. If your image is bigger than 350 pixels in width, it's polite to put them behind an LJ cut because they are unfriendly to some friends pages (like mine, my layout is narrow). All of this will only show up when you either click the link in the post or when you click the link on the bottom left.</lj-cut>

And now you can read this on the main page again.