I am looking for guidance in developing a customized rss mini feed that I want to display in the lower corner of a tumblr page. I've googled for days looking for a clear and thorough explanation of how to do it and nothing has worked.

I need a step by step on the post-html process of developing one. I'm not too familiar with javascript or php, so any help would be much appreciated. I've looked into using widgets, but nothing I've found is customizable enough to make it look the way I'd like it to look. The lower right hand corner of the page below is what I need to make this look like.

http://danchaplinlaw.com/images/TumblrMock-Up.jpg