You always need a DOCTYPE in your code. So make the top look like this:
Then be sure to close out the body and html tags at the bottom:
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<link href="css/main.css" rel="stylesheet" type="text/css">
<title>findFriends - A new social Network</title>
That will probably do it. The validator is your friend to help find bugs!
There should be no need for separate style sheets for IE, unless perhaps you're trying to make this work in IE6/7.