Welcome to the Q&A Forum

I would simply leave all PDFs as dofollow - unless they are not unique or if any of PDFs have content that has already been published on the site (html/ page). Are all 52 PDFs have same content? If so I would let get 1 of them indexed and use NOFOLLOW/NOINDEX  on rest  (use robots.txt) and may be even use 'canonical' to prevent the others from being indexed and cause any potential duplicate content issue. Some good reference for you: http://www.seomoz.org/q/can-pdf-be-seen-as-duplicate-content-if-so-how-to-prevent-it http://www.seroundtable.com/archives/021584.html

Good to hear, If you redirect on mass to the home page, they will likly be dismissed