How do I change this CSS to look the same on a Mac as a PC?

That's not enough info.  The code you posted looks the same in all browsers including Safari.  Can you give us a link or the complete page code?

Below that all I have is this:

<div>
blah blah blah a bunch of text
</div>

This is what it look like in all browsers for me.  I just put an image I had in there.  The divs are overlapping.
XbrowserCSS.jpg

DaveBaldwin is right, I have the same view.

I made some small changes but it still looks bad with Safari:

<div style='padding: 30px; border: 0px solid #000000; width: 800px;'>

   <div style='float:left; width:390px; height:75px;'><img border='0' src='./images/logo.gif'></div>
   
    <div style='float:right; width:390px; height:75px; text-align:right; padding-top: 35px;'><font size='2'><u><b>STUDENT CLUB ACTIVITIES</b></u></font></div>
      
       <div style='display:block; text-align:center; width:780px; height:50px; font-size:17px; font-weight:bold;'>RELEASE AND WAIVER OF LIABILITY, ASSUMPTION OF RISK AND INDEMNITY AGREEMENT</div>
      
         <div style='font-size:14px;'>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum in velit vel risus semper ultrices et eu lectus. Curabitur luctus sollicitudin mauris, varius aliquam est ullamcorper et. Sed semper libero lorem. Vivamus sapien nisl, mollis in dictum at, lobortis at diam. Donec luctus pretium diam non adipiscing. Nullam a nunc est. Aenean felis libero, scelerisque non iaculis at, placerat id enim. In augue diam, pellentesque id cursus in, elementum nec libero. Sed quis sapien urna. Nunc nec metus eget diam iaculis interdum. Fusce sem sem, tincidunt et gravida a, faucibus non purus. Morbi pellentesque, erat id malesuada hendrerit, dolor risus dapibus lorem, eu convallis magna nisl et neque.</div>         
         </div>

Also I've attached a screentshot from Safari.
safari.png

It doesn't look the same in all browsers.

In IE, Firefox and Chrome the text does not overlap.

float. left; worked.

thanks