Question: Our client has several specification sheets in pdf format for many of their products. What is the best or easiest way for them to add a downloadable PDF to each product page. (Some PDFs fit many products).

UPDATE: I found a very useful extension for this <http://amasty.com/product-attachments.html>

Answer: 
I've got a better way.  

Install this extension: [Etatva Extension](http://www.magentocommerce.com/magento-connect/product-file-attachment-by-etatvasoft.html)

After installing, add this line to view.phtml. 

```
echo $this->getLayout()->createBlock('files/product_view')->setTemplate('files/files.phtml')->toHtml();  

```

Save it, clear cache, log out, re log in. Go to `System>>Configuration`, you should see that extension in left panel. Play with settings so that pdf files can be uploaded in backend.  

Then add a new product, upload pdf. Then add a custom attribute, make it visible in front end. In backend, use an anchor tag like this for that custom attribute. 

```
<a href="linkwherecustompdfsare stored" alt="pdfdownloader">PDF Downloader</a>  

```

Save it, refresh front end and Voila!!  

You should see a link in front end, clicking on it will download the pdf.  

Tested and verified in Magento CE 1.9.0.1 :)
Another possibility is to use an extension which does exactly what you want to do.
There exists a free extension for this purpose:

<http://www.magentocommerce.com/magento-connect/pdf-for-every-product-8631.html>

Another one which is free for up to 1000 products is this one:

<http://www.magentocommerce.com/magento-connect/pdf-for-every-product-8631.html>