Just passed my CCNA Voice exam and thought I'd share with you my experience. Firstly I'll talk about the exam (without breaking any of the NDI rules). The exam was easier than I expected, after seeing the first 4-5 questions I then realised how easy the rest was going to be and without sounding too cocky, I already knew I passed before I reached my 7th question. I am very happy that I've passed so now I can venture onto the CCVP track with a clear understanding of the basics. It is very good that Cisco brought out the CCNA concentration exams but I do feel let down with the price for the exam compared to the questions asked.
There are only a few books or resources out there tailored for the CCNA Voice, so my approach was to watch the CBT Nuggets, read the Cisco Press book and then I read the Cisco Press CVOICE book 3rd edition. When I say read, I merely glanced over the chapters of CVOICE and read each summary chapter. If and when you do this, it will tie all you've learnt from your CCNA Voice resources together. Also, here's a handy tip.. Go through the CVOICE questions listed at the end of each chapter (in the Cisco Press 3rd edition book). If you can answer these questions with ease, then you're confident enough to take your CCNAV exam.
I also noticed there isn't much content for the UC500 configurations out there tailored for the CCNAV exam, so I'd urge you to download some PDFs on the UC500. Nothing too heavy, just basics and screenshots to get yourself familiar with working around this. I wouldn't suggest you got yourself a working lab setup for the CCNAV, but just seeing a few screenshots and knowing which tabs you need to click on to do XYZ (simple stuff) with help you out. I downloaded a good PDF from Cisco's website. Finally I read the CCNA Voice Quick Reference sheet which tied everything all in together.
Having already read the content for the CVOICE exam I may book this exam for next month. I'm sure there are a few details to know and master and maybe some good ol sims that'll expect one to configure.
So all in all, very easy exam (compared to the others I've done CCNA, CCNP) and happy to now work on my CCVP track. Good luck to anyone taking the CCNAV (although I'm sure you don't need it).