Featured Image in Global Posts

I'm not much of a programmer, how would I go about changing the avatar in the recent global post widgets to being the featured image in the post or the first image uploaded to a post?

I'm also looking to be able to display blocks of posts from different blogs on the site. Since my network isn't open to registration I can make sure whatever is needed in each blog to pull it from (like a featured category), but I'd like to be able to showcase a block of posts from each blog with the post image rather than the author avatar. Ie 4 posts from blog id 3 with the post image.

I'm beginning level with php but good with css so when I look at the example code I was given

<br />
switch_to_blog($blog_id):<br />
get_post_mets($post_id, 'whatever');<br />
restore_current_blog();

Is confusing to me. If I saw the code in action I could likely make it work.

Any help would be appreciated. Basically I'm trying to build a magazine type site where different topics are in their own blogs so I can brand each blog differently.

Any help would be greatly appreciated.