To add hyperlinks to Excel, you can type the corresponding URL, add hyperlinks using the Link feature or use the HYPERLINK Function.

You can insert or add Header and Footer in Excel spreadsheet using this tutorial. Insert page number, current date and time, etc.

If you want to add a footer to an Excel spreadsheet, click the "Insert" tab on the ribbon menu. Then click "Header & Footer" within the "Text" group of options.

A complex Excel 2007 workbook could require multiple sheets. By default, Microsoft provides three sheets on each workbook, but you can add as many as you need.