Your details were a little vague on this request for help, also you didn't provide any attempts at your jquery, so basically I'm giving you the simplest form of what you're asking for.
Here is the codepen
Note
CSS Reset in codepen was used, and the jquery library must be called in order for that to work in whatever you do.
Also, since this question was rather lazy I didn't provide you any IE fallbacks because I felt like being lazy :).
HTML
<link href='http://fonts.googleapis.com/css?family=Open+Sans:400,700' rel='stylesheet' type='text/css'>
<div id="overlay" class="info">
<a id="show-me" href="#">GO</a>
<span>Title</span>
<p>Some information text</p>
<div id="hidden-div">
<div class="content">
<p>Some Content Here</p>
<a id="close" href="#">✖ Close Overlay!</a>
</div>
</div>
</div>
CSS
*,
*:before,
*:after {
box-sizing: border-box;
}
body,
html {
margin: 1em;
font-family: 'Open Sans', sans-serif;
}
a:link {
text-decoration: none;
color: #DB1F1F;
}
.info {
background-image: url('http://placehold.it/400x200');
background-repeat: no-repeat;
background-size: cover;
background-color: #E0E0E0;
padding: 8px;
height: 200px;
width: 400px;
position: relative;
z-index: 1;
}
#hidden-div {
display: none;
position: absolute;
height: 200px;
width: 400px;
top: 0;
left: 0;
background: rgba(205,36,36,.5);
display: none;
z-index: 0
}
.content {
position: relative;
top: 50px;
}
.content p {
margin: .5em 0;
color: #fafafa;
}
.content a:link,
.content a:visited {
color: #950000;
font-weight: 700;
}
JQUERY
$(document).ready(function(){
$("#show-me").click(function(){
$("#hidden-div").toggle("slow");
});
$("#close").click(function(){
$("#hidden-div").toggle("fast");
});
});