http://css3buttongenerator.com/
sample button:
.btn {
-webkit-border-radius: 0;
-moz-border-radius: 0;
border-radius: 0px;
font-family: Arial;
color: #ffffff;
font-size: 17px;
background: #3498db;
padding: 10px 20px 10px 20px;
text-decoration: none;
}
.btn:hover {
background: #3cb0fd;
text-decoration: none;
}