Google
Button Elements

Basic Button
Change Font Color
Change Background Color
Gradient Background
Border Outline
Double Border Outline
Button with Hover
Button with Image
Hover Image Button

CSS Code
/* Change Font Color: */
.button-color-font {
    color: #008800;
}

/* Change Background Color: */
.button-color {
    background-color: #008800;
    color: #FFFFFF;
}

/* Gradient Background: */
.button-bg {
    background: url(button_bg.gif) repeat-x;
    border: 1px solid #bfa277;
}

/* Border Outline: */
.button-border {
    border: 1px solid #981234;
    background-color: #BFD5EE;
}

/* Double Border Outline: */
.button-border-2 {
    border: 3px double #981234;
    background-color: #BFD5EE;
}

/* Button with Hover: */
.button-hover {
    border: 1px solid #981234;
    background-color: #BFD5EE;
}
.button-hover:hover {
    border: 1px solid #BFD5EE;
    background-color: #981234;
    color: #FFFFFF;
}

/* Button with Image: */
.button-image {
    background: #EBE3CD url(Portal.gif) no-repeat left center;
    vertical-align:middle; 
    border: 1px solid #969184;
}

/* Hover Image Button: */
.button-hover-image {
    height: 22px;
    width: 100px;
    background: transparent url(button1.gif) no-repeat top left;
    border: none;
}
.button-hover-image:hover {
    background: transparent url(button2.gif) no-repeat top left;
    border: none;
    color: #800000;
}