Here is a good article:
http://www.sitepoint.com/style-web-forms-css/

.sections section{float:left; width:100%; margin: 0 0 15px 0;}
.sections section > *{float:left}
.sections section label{width:200px;}
form {
background: -webkit-gradient(linear, bottom, left 175px, from(#CCCCCC), to(#EEEEEE));
background: -moz-linear-gradient(bottom, #CCCCCC, #EEEEEE 175px);

margin:auto;
padding:10px;
position:relative;
width:95%;
font-family: ‘Carrois Gothic’, sans-serif;

-webkit-border-radius: 10px;
-moz-border-radius: 10px;
border-radius: 10px;
border: 1px solid #999;
border: inset 1px solid #333;

-webkit-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
-moz-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
}

fieldset{position:relative;}

input[type=”text”]{
width:95%;
height: 25px;
display:block;

border: 1px solid #999;
-webkit-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
-moz-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);

-webkit-border-radius: 3px;
-moz-border-radius: 3px;
border-radius: 3px;
}

input[type=”button”], input[type=”submit”]{
height: 25px;

border: 1px solid #999;
-webkit-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
-moz-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);

-webkit-border-radius: 3px;
-moz-border-radius: 3px;
border-radius: 3px;
}

textarea {
display:block;
width:95%;
height: 100px;

border: 1px solid #999;
-webkit-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
-moz-box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);
box-shadow: 0px 0px 8px rgba(0, 0, 0, 0.3);

-webkit-border-radius: 3px;
-moz-border-radius: 3px;
border-radius: 3px;
}