Colocando uma tela de loading

Olá. Gostaria de implementar uma tela de loading com esse código. A dúvida é como.

html

<!DOCTYPE html>
<link  href="theme.css" rel="stylesheet" type="text/css">
<html>

<body class="Fundo">
	<div class="sk-cube-grid">
		<div class="sk-cube sk-cube1"></div>
		<div class="sk-cube sk-cube2"></div>
		<div class="sk-cube sk-cube3"></div>
		<div class="sk-cube sk-cube4"></div>
		<div class="sk-cube sk-cube5"></div>
		<div class="sk-cube sk-cube6"></div>
		<div class="sk-cube sk-cube7"></div>
		<div class="sk-cube sk-cube8"></div>
		<div class="sk-cube sk-cube9"></div>
	</div>
</body>

</html>

CSS

.sk-cube-grid {
	width: 40px;
	height: 40px;
	margin: 300px auto;
	padding: 0px 0;
}
.Fundo{
	background-image: url(fundo.png);
	background-repeat: no-repeat!important; 
}
.sk-cube-grid .sk-cube {
	width: 33%;
	height: 33%;
	background-color: #FFFFFF;
	float: left;
	-webkit-animation: sk-cubeGridScaleDelay 1.3s infinite ease-in-out;
	animation: sk-cubeGridScaleDelay 1.3s infinite ease-in-out; 
}
.sk-cube-grid .sk-cube1 {
	-webkit-animation-delay: 0.2s;
	animation-delay: 0.2s;
}
.sk-cube-grid .sk-cube2 {
	-webkit-animation-delay: 0.3s;
	animation-delay: 0.3s;
}
.sk-cube-grid .sk-cube3 {
	-webkit-animation-delay: 0.4s;
	animation-delay: 0.4s;
}
.sk-cube-grid .sk-cube4 {
	-webkit-animation-delay: 0.1s;
	animation-delay: 0.1s;
}
.sk-cube-grid .sk-cube5 {
	-webkit-animation-delay: 0.2s;
	animation-delay: 0.2s;
}
.sk-cube-grid .sk-cube6 {
	-webkit-animation-delay: 0.3s;
	animation-delay: 0.3s;
}
.sk-cube-grid .sk-cube7 {
	-webkit-animation-delay: 0s;
	animation-delay: 0s;
}
.sk-cube-grid .sk-cube8 {
	-webkit-animation-delay: 0.1s;
	animation-delay: 0.1s;
}
.sk-cube-grid .sk-cube9 {
	-webkit-animation-delay: 0.2s;
	animation-delay: 0.2s;
}

@-webkit-keyframes sk-cubeGridScaleDelay {
	0%, 70%, 100% {
		-webkit-transform: scale3D(1, 1, 1);
		transform: scale3D(1, 1, 1);
	} 35% {
		-webkit-transform: scale3D(0, 0, 1);
		transform: scale3D(0, 0, 1);
	}
}

@keyframes sk-cubeGridScaleDelay {
	0%, 70%, 100% {
		-webkit-transform: scale3D(1, 1, 1);
		transform: scale3D(1, 1, 1);
	} 35% {
		-webkit-transform: scale3D(0, 0, 1);
		transform: scale3D(0, 0, 1);
	}
}

coloque seu codigo na tag code para podermos visualizar o codidgo

Ok como eu faço isso?