I'm using wordpress2.5 and am trying to get the thumbnail photos to appear in the post descriptions on the first page. I already have the (medium) size photos uploaded in my media and showing up in my posts with no problem.
You need to program it into the theme, using the "Custom Fields" option (you'll find this in the admin/new post/bottom of the page). Many themes (like Revolution) have this built-in. I'm not sure how he did it, but in order to get the thumbs to appear, you just upload the image to your server, go to that Custom Fields area I mentioned before, and set it to "Thumbs" and copy and paste the image link next to it. Then, the thumbnail appears next to the post on the front page.
Thats exactly what I've been doing and it hasn't been taking. Maybe I need to reduce picture size or something. You can view it by going to the home page of my first signature (debt consolidation) thanks!