Yes, you can. By using DIVs. Divs are used for layout, unlike tables, which are used for presentation of data such as charts.
Yes, you should validate your code using W3’s validator located at: http://validator.w3.org/
EDIT: I forgot to mention, when using DIVs, you should use CSS to STYLE the page, and have it in a seperate file (.css). You can import the file by using the following command.
<link rel="stylesheet" type="text/css" href="location/of/file.css" />