OK CSS is some what like HTML, but maybe a lil bit harder. CSS means cascading stylesheets. I suggest you stick with HTML. You CSS only if u need to.

To add an image background to your Site:
<style type="text/css"><!-- body{background:url(image url);background-attachment:fixed} //--></style>
The background is FIXED meanin it wont move on ur screen.

To add an image background and a color background to your Site:
<style type="text/css"><!-- body{background:#000000 url(image url);background-attachment:fixed} //--></style>
Addin a color background is good so just incase the image url does not work the color will show instead.

To add CSS to your Links:
<style type="text/css"><!-- a:link{font-family:matisse;font-size:12px;color:#000000} a:active{font-family:arial;font-size:12px;color:#FFFFFF} a:visited{font-family:matisse;font-size:12px;color:#808000} a:hover{font-family:tempus sans itc;font-size:12px;color:#FFFFFF} //--></style>
[a:link] This is for Links that have not yett been visted
[a:active] Links that have been clicked on
[a:visited] Links that have already been seen
[a:hover] Links for when your mouse is on
You can add Borders [border:#99000 2px solid] and or Backgrounds [background:#990000]

To add color to ur scroll bar:
See the scroll bar is Red.
<style type="text/css"><!-- body{scrollbar-base-color:#990000} //--></style>

To add different colors to ur scroll bar:
See the scroll bar is different colors.
[scrollbar-track-color] This part of the scroll bar is the bottom. Its white here.
[scrollbar-highlight-color] Here it is Teal.
[scrollbar-3dlight-color] 3D Light is Red
[scrollbar-darkshadow-color] Shadow here is Blue
[scrollbar-shadow-color] Here it is Olive Green
[scrollbar-arrow-color] Color od the arrow, here it is Green
[scrollbar-face-color] Color of the scroll bar, here it is black.

<style type="text/css"><!-- body{scrollbar-track-color:#FFFFFF;scrollbar-highlight-color:#008080;scrollbar-3dlight-color:#990000;scrollbar-darkshadow-color:#0000FF;scrollbar-shadow-color:#808000;scrollbar-arrow-color:#008000;scrollbar-face-color:#000000} //--></style>

To change a border on a Table Or Div:

Solid Border

Double Border

Inset Border

Outset Border

Dashed Border

Dotted Border

just add the name to da code style="border:#99000 2px solid" change solid to whatever which one you want

Too add a border to your page: Same as for the DIV or Table change the sytl of the border to which one you want
<style type=text/css><!-- body{border:#990000 5px solid} //--></style>

Too addmore then one color to the border:
<style type=text/css><!-- body{border-right:#990000 5px inset;border-left:#000000 5px inset;border-top:#990000 5px inset;border-bottom:#FFFFFF 5px inset} //--></style>