Wrap each stanza in a <div>, and each line in a <div> or <p>. Do not use <br/> to break lines, because it gives you less control on what happens when a line has to break because it's longer that the screen/page width. Then assign a CSS similar to:
Code:
div.stanza {
margin: 0.5em 0 0 2em; /* some vertical separation and left margin for stanzas */
}
div.stanza p {
text-align: left; /* you don't want poetry justified */
text-indent: -3em;
margin-left: 3em; /* this two values make wrapped lines indented */
}