For troubleshooting, Google Chrome has a lot of development tools already built in.
Want to know most of the information Firebug tells you but don’t want the Firefox overhead?
Right Click on any element and select “Inspect Element” from the context menu. You can real time edit Style Sheet entries and HTML code to attack any display issue in real time. Don’t like it, reload and try again. When you get it right, then edit your CSS and php templates to output the proper HTML and Styles.
As to editing templates and layouts for Magento, There is no Point’n Click ™. Layouts control what blocks will be displayed, Templates control what’s in the blocks you’ll be displaying. The rest is learning PHP coding built on a Zend Framework. It requires self-education and experimentation in PHP programming skills. Programming environments like Eclipse can help, though you can get by with a programmer’s editor like TextPad set up for php code highlighting in .php and .phtml