Trying to read a pdf like a magazine is painful , particularly on a e-ink display , couple that with small display. I use calibre to convert. It does OKish job. Better is get epub files rightway for more compatibility and easy , painless job or transferring and reading etc.
Better stick with epub itself . PDF rendering takes too much and i dont think these book reader have enough power to render them good enough and fast enough.
As for my issue where my nook died , i sent it back to US , got it back after a long long time . It came few months back , got a cover case for it . I would advice everyone to get some basic Hard case for these fragile e-book readers.