1) You want the Firefox Web Developer extension, which will let you see the class/id and other information associated with any element on the page. When you have that, you can easily find the item to edit in your stylesheet.

You can also view source and look for the class or id just before the element you want to style.


2) In /includes/templates/your_template/common/tpl_header.php, you will find blocks of code with <!--bof xxxx--> and <!--eof xxxx--> comments around them. You can move any of these blocks around in the file (just not inside another block) to get the order you want.