If you have designs on the csszengarden site, like me, the following will help:
/* SCHEMA */
/* *** PAGE BLOCKS *** */
/* basic elements */
div { border:1px dashed black; }
body { background#666666:; }
a, a:link, a:hover, a:visited, a:active { color:yellow; font-weight:bold; }
/* container */
#container { background:#999999; }
/* intro */
#intro { background:maroon; }
#pageHeader { background:silver; }
#quickSummary { background:#ff0000; }
#preamble { background:#ff0066; }
/* supportingText */
#supportingText { background:#000066; }
#participation { background:#000099; }
#benefits { background:#0000cc; }
#requirements { background:#0000ff; }
#footer { background:#6699cc; }
/* linkList */
#linkList { background:#006600; }
#linkList2 { background:#009900; }
#lselect { background:#00cc00; }
#larchive { background:#99cc00; }
#lresources { background:#ccff00; }
/* extraDivs */
#extraDiv1 { background:red; }
#extraDiv2 { background:orange; }
#extraDiv3 { background:yellow; }
#extraDiv4 { background:green; }
#extraDiv5 { background:blue; }
#extraDiv6 { background:indigo; }
Just put it at the end of your style sheet as you work on it.