I typically use the following css:
.indent {
margin: 0;
text-indent: 1em
}
.flush {
margin-top: 1.25em;
margin-bottom: 0;
text-indent: 0
}
Then the text goes:
<p class="indent">This paragraph has the first line indented. Lorem ipsum dolor sit amet, id euismod, consectetuer nec aliquam. Sagittis amet, nec nunc, qui accumsan turpis. A tempus, class aliquam tempor, eget wisi. Enim duis eros, ut eros. Mauris ut lectus, lorem semper, leo ut convallis.</p>
<p class="flush">This paragraph will appear with a blank line above it and without an indent. Adipiscing posuere, lobortis nec nec, ipsum iaculis. Aliquam posuere dolor, leo nulla, nulla mi. Wisi ut commodo, justo tellus vel. Vitae occaecati platea. Nam a sapien, porta lacus platea, pellentesque eleifend.</p>