No tricks - just upload it to the server and link to it. The one thing you should be aware of is that not all browsers will display the form correctly and let the user fill the form and submit it via email: If the browser is using the Adobe Acrobat or Adobe Reader plug-in to display the PDF file, then there is no problem, but if you are dealign with a browser that either does not default to Adobe's PDF viewer (e.g. Firefox), or does not allow the Adobe plug-in to display the PDF file, things will not work as smoothly: The user will very likely have to download the PDF file and open it in Acrobat or Reader in order for your form to work correctly. And, if anybody is opening the form on a mobile device, all bets are off in regards to what will work.
I would add instructions to the download link that tell your users that they need to download the file to a desktop computer and use Adobe Acrobat or the free Adobe Reader to fill out and submit the form.