/*TOPO
-------------------------------------------------*/

#topo {
text-align:center;
margin: 50px 0px 0px;
}

/* Menu Fixo
-------------------------------------------*/
#alinhamentohorizontal{
width: 1050px;
}

#menufixo{
font-family: tahoma;
background: #000000;
heigth: 40px;


position: fixed;
 top: 0;
 left: 0;
 width: 100%;
 z-index: 99;

}


#menu {
padding: 10px 0px;
}

#menu a{
color: #fff;
padding: 0px 20px;
}

#menu a:hover{
color: #000;
}

Código

<div id= 'menufixo'>

      <center>
     <div id='alinhametohorizontal'>

<div id='menu'>

<a href =''> HOME</a>
<a href =''> SOBRE</a>
<a href =''> CONTATO</a>
<a href =''> BLOGS QUE VISITO</a>


Fica assim