Re: How can I add a latest tweet box over this image?

This is a design composition.  It is NOT a web page layout.  

http://willlh.com/Website%20Design/Home%20Page%20Website%20Design.jpg

You have much more work to do before you can use this for a web site.   Work through the following 3-part tutorial.   Although written for Fireworks, the procedure is basically the same no matter which graphics app you use.

Taking a Fireworks comp to a CSS Layout in DW

Part 1 - Initial Design

http://www.adobe.com/devnet/dreamweaver/articles/dw_fw_css_pt1.html

Part 2 - Markup preparation

http://www.adobe.com/devnet/dreamweaver/articles/dw_fw_css_pt2.html

Part 3 - Layout and CSS

http://www.adobe.com/devnet/dreamweaver/articles/dw_fw_css_pt3.html

Incidentally, don't use spaces or special characters in folder or file names for the web.  This will create problems for you later.  If you wish, you can use underscores _ or hyphens - between words.  But no spaces.

Nancy O.