Hi there,
Ive uploaded an image into a blog. However, i want it to display like this:
Small images when viewing the category/front page
http://www.tripwiremagazine.com/category/css
Then the full image when viewing the full blog
http://www.tripwiremagazine.com/2010/06/10-seriously-useful-online-css-code-generators.html
You should check out Mark Jaquith's post: http://markjaquith.wordpress.com/2009/12/23/new-in-wordpress-2-9-post-thumbnail-images/
You can set a featured image when creating a post, then use the code in Mark's post to display the image on the different parts of the site.
If your theme has a category.php template, you'll want to edit that for the small image, and edit single.php to display the full size image.