Mouse over and Mouse out with CSS

Declare anchor tag
<a href="../UserPages/wpWelcome.aspx" id="aHome"  ><span>Home </span></a>

Write css for anchor tags(but careful that it will apply for all anchors)

a
{
    color: Blue;
}

a:hover
{
    font-weight: bold;
    text-decoration: underline;
    color: orange;
}