The CSS3 way (no extra markup)

Target the first character of the first paragraph using pseudo class selectors. No extra markup needed, but no IE < 9 support.

<p>
  Just a normal sentence.
</p>

p:first-child:first-letter {
  color: #903;
  float: left;
  font-family: Georgia;
  font-size: 75px;
  line-height: 60px;
  padding-top: 4px;
  padding-right: 8px;
  padding-left: 3px;
}