i'm just trying to figure out what all the references mean

I think that's great!

In CSS, you can use whatever terms you'd like. Generally in most designs though, a header is the top part of a web page and the site title is one of the components inside the header. So, if you were setting a background image for example, you might want to use the header id or class whereas if you wanted to change the color or font of the blog name (or site title) then you would want to make a rule just for that.

You may also want to check out some beginner tutorials. I think you'll like them.
http://en.support.wordpress.com/css-basics/
http://www.htmldog.com/guides/cssbeginner/

is the a "search code/string" that I can use to help me find what I'm looking for within the CSS code?

That's one way, yes.

I would recommend a couple things. One, use the original stylesheet link below the editor on the Appearance → Custom Design → CSS page to see how the theme author added code.

If you use one of the tools I mentioned, the browser web inspector or Firebug for Firefox, then you can right-click on an element on a page and select 'Inspect Element' and it will show you the HTML for what you clicked on as well as all of the relevant CSS that applies to that element. The nice thing about that view is that you can see what later CSS overrides earlier CSS because if something gets overridden it will show up crossed out.

is the a "search code/string" that I can use to help me find what I'm looking for within the CSS code?

The reason I want to find the reference is to, see and learn, the "logical layout" of the CSS format. I need to know what comes first, second, etc...

It's a quirk that I have... Thanks very much... :)

#site-title {
  margin-right: 0;
}

Also, I would like to remove the "search" box... can i do this by deleting the CSS code for them or is that done only in HTML?

In the Twenty Eleven theme, there is a search form built into the header area. That one you need to remove with CSS. This should do the trick:

#branding #searchform {
  display: none;
}

now I need to figure out how to change all the "tab and Text" colours to White....

Looks like you've figured out how to change the top menu background to black and link colors to white. Do you still need any help with that part?

To change the color of the submenu items in the top menu to white, add this:

#access ul ul a {
  color: #eee;
}

now I need to figure out how to change all the "tab and Text" colours to White....

Also, I would like to remove the "search" box... can i do this by deleting the CSS code for them or is that done only in HTML?

Thanks,,,

hope that is correct... thx

My question is, do I apply the actual colour code to each "back ground" reference and if so, is there a search function that will help me?

Thanks, Monaleasaa