Just took the jncia exam this morning and passed, really happy about it-

I always like hearing what people used for studying and found it encouraging when others passed, so I'm doing the same.
I already had my CCNA-R&S which helped out a lot, but here is what I used to study:
Junos-Genius app (all the time, for the past 3 months)
the 2 PDFs from Juniper's website
I also used olive running on virtualbox, which was really great as it helps learning syntax
CBT nuggets JNCIA (michael shannon) - these were ok, though I think you don't really need these to pass. Juniper gives enough info on their site with the PDFs and videos (one video in particular is geared toward those with cisco knowledge, which was great).
I had the Junos for Dummies book on my kindle app. Though I'm not sure this is necessary for passing the exam, I do feel it was worth it as the goal isn't just the exam but getting the knowledge and (hopefully) putting it to use.
Good luck everyone with your Juniper studies! I can't wait to keep learning more!