If you want to change background image and display content on hover effect this code will help you.

lets say if you want to show a content only when you move a cursor on an image div, and when image changes it will display the content or description of the image which is set in the background of  first image.

html:

<div class="feature">
	<img alt="" src="feature01.jpg" />
    <a href="#">
         <span class="caption">glass</span> // this is the description of image which will appear when user hover on image //
    </a>
</div>

css:

	.feature{
		float: left;
        position: relative;
	}
	.feature a {
        display: block;
        position: absolute;
    	left:0;
    	right:0;
    	top:0;
    	bottom:0;
    	background:#94C83D;
    	display:none;
    }
	.feature img {
        width: 100%;
        display: block;
    }
	.feature:hover a{
		display:block;
	}
    .feature span {
        color: #fff;
        display: none;
        font-size: 36px;
        font-weight: 100;
        letter-spacing: 1px;
        text-indent: 4%;
        text-transform: uppercase;
        width: 100%;
    	position:absolute;
    	top:40%;
    	display:block;
    }