You can send an attachment along with your email templates by navigating to Tools -- My Files and Folders and hover over the My Office Documents section and click add file
Once you've uploaded your file you can go to Email -- My Email Templates and click the pencil icon to the left of the template you want to add a file to.
Right above the Upload Image or File button you'll see a rectangle labeled Attachments from My Files & Folders where you can click the Show Attachments link.
Clicking that will expand out this section and allow you to check off documents you want to have attached to this email when it sends out.
Hit Save Template to complete your changes.
Now whatever files you've attached to that template will go out as an attachment every time that email is sent.