Newbie question – Weird category behavior

I’m sure I’m missing something simple, but I need help. I created a post with a link to my downloads page; the post is assigned to the “web design class” category. On the main page, the post looks fine, and the link works, but if I click on the “web design class” category, the post doesn’t show up at all.

Also, is there a way to set a default so that posts on the category pages are full-length and not shortened? I know that I can have shortened posts on the main page, but I want the full posts on the category pages.

You can see it at https://jesszimmerman.com