A quick link to something I found, a free book on copywriting by Tom Albrighton. The details are here: Free copywriting ebook: The ABC of Copywriting and all you have to do is tweet a link to the post (there are options for LinkedIn or FaceBook as well).
The whole process takes maybe thirty seconds and the book is presented as a PDF file. The book is just under 100 pages and (at first glance) is well written and is based on content from the ABC Copywriting Blog. If you have a Kindle (or a tablet with the free app) don’t forget you can send yourself a PDF file and it will then appear as a Kindle book.
Do let me know of any other freebies I should mention.