<style type="text/css">
.tooltip {
border-bottom: 1px dotted #000000; color: #000000; outline: none;
cursor: help; text-decoration: none;
position: relative;
}
.tooltip span {
margin-left: -999em;
position: absolute;
}
.tooltip:hover span {
border-radius: 5px 5px; -moz-border-radius: 5px; -webkit-border-radius: 5px;
box-shadow: 5px 5px 5px rgba(0, 0, 0, 0.1); -webkit-box-shadow: 5px 5px rgba(0, 0, 0, 0.1); -moz-box-shadow: 5px 5px rgba(0, 0, 0, 0.1);
font-family: Calibri, Tahoma, Geneva, sans-serif;
position: absolute; left: 1em; top: 2em; z-index: 99;
margin-left: 0; width: 250px;
}
.tooltip:hover img {
border: 0; margin: -10px 0 0 -55px;
float: left; position: absolute;
}
.tooltip:hover em {
font-family: Candara, Tahoma, Geneva, sans-serif; font-size: 1.2em; font-weight: bold;
display: block; padding: 0.2em 0 0.6em 0;
}
.classic { padding: 0.8em 1em; }
* html a:hover { background: transparent; }
.black {padding:4px; background: #000; border: 1px solid #FFAD33; color: #fff; }
.navy {padding:4px; background: #000080; border: 1px solid #dadada; color: #fff;}
.blue {padding:4px; background: #0000FF; border: 1px solid #dadada; color: #fff;}
.teal {padding:4px; background: #008080; border: 1px solid #FFAD33; color: #fff; }
.aqua {padding:4px; background: #00FFFF; border: 1px solid #FFAD33; color: #000; }
.silver {padding:4px; background: #C0C0C0; border: 1px solid #FFAD33; color: #000; }
.gray {padding:4px; background: #808080; border: 1px solid #FFAD33; color: #000; }
.yellow {padding:4px; background: #FFFF00; border: 1px solid #FFAD33; color: #000; }
.green {padding:4px; background: #008000; border: 1px solid #FFAD33; color: #000; }
.olive {padding:4px; background: #808000; border: 1px solid #FFAD33; color: #000; }
.lime {padding:4px; background: #00FF00; border: 1px solid #FFAD33; color: #000; }
.red {padding:4px; background: #FF0000; border: 1px solid #FFAD33; color: #fff; }
.maroon {padding:4px; background: #990000 ; border: 1px solid #FFAD33; color: #fff; }
.white {padding:4px; background: #FFF; border: 1px solid #FFAD33; color: #000; }
.fuchsia {padding:4px; background: #FF00FF; border: 1px solid #FFAD33; color: #000; }
.purple {padding:4px; background: #800080; border: 1px solid #FFAD33; color: #fff; }
</style>
<a class="tooltip" href="#">TEXTO<span class="color">CONTENIDO DEL TOOLTIP
</span></a>
Y listo es todo en este tutorial como ven es muy fácil, hasta la próxima.