I would love if there was an easy way to email a pdf or even send an excel sheet would be great. I work for a Wholesale Florist and I fax and email daily specials out to customers. Currently when I email specials, the files are created in excel, then I have to create a pdf, and then create a jpg of the file as well. Insert the jpg in the email and link to the actual pdf. Not exactly elegant.
Depending on your audience, one thing I have started to do is utilize a link for a public share folder OR private share folder into an online storage facility. So I sign up with live.com, only to use their email, and keep the other applications from installing. Then I go to skydrive.live.com and create a specific folder for my pdf file. upload the PDF and set the folder to public. Skydrive will offer you link you can pass along within your newsletter and the people can download through that link. If you want to shorten or try and customize the link, you can try and go to http://www.tinyurl.com and customize the referring link. Some on line storage facilities have a way to share like dropbox and maybe box.net. I know all three of these to be worthy and honest vendors of this technology, but be careful about randomly looking for a vendor that is not well known as a public share group. Additionally, you can convince your audience to follow your Twitter or Blog or Facebook account, and in turn increase your signup numbers and offer links ONLY through there... which will utilize this these public share folders.
I would be happy to assist you with creating a email using your PDF. Once you have your PDF saved as a image, then you can insert the image as a standard image in your Constant Contact account.
However, I would suggest not sending a email with just your PDF in the body of the email, doing so can cause deliverability problems. Here is a FAQ explain why not to create a single image.