Links on this page have 4 parts. You can start a link on a new line
Here's the example I gave in the comments on the webpage:

<a href="youFileName.xls"> Click for the  2007 wetlands spreadsheet </a><br />

Part 1
<a href="youFileName.xls"> 

Tells the visitor's web browser that the next line of text is a link to a file named
youFileName in the same folder as the page. Furthermore, it is an .xls file, so it needs
top be opened in excel or saved. The structure, including quotations, is very important.
Other examples:
<a href="letters.doc">  Word document
<a href="adobeLetter.pdf"> PDF file.

Please note that your document type is determined by the document itself, not by the link.
Don't upload an excel spreadsheet and create a pdf link to it. Use the correct filename and extension.
Everything is case sensitive

Part 2 
Click for the  2007 wetlands spreadsheet 

Easy part. This is the visible part of your link. You can type anything in here.

Part 3
</a>

Closes the link. Without it, all the rest of the text on the page becomes a giant link

Part 4
<br />

Line break.