Best way to convert PDF to epub
Calibre will try to convert it for you, but it will usually have lots a formatting issues.
I have tried alot of ways to convert PDFs to other formats, and this is by far the best.
Open your pdf in adobe, click edit-->Copy file to Clipboard
Open word or wordpad, and paste the file in.
This will get it into word with the formatting intact.
Save as an RTF, and use calibre to convert to whatever format you want.
I use Mobi, but my kids all have Itouches so they need EPUB for stanza. Once you have it in RTF calibre can handle any other conversions you need.