The differences between the NKJV and KJV Bible translations

I am planing to get one of these translations for my personal use. If these are _too different_ from one another, I would like to get both. I love to compare _(for my personal study)_ different versions _(even different languages within the same version)_ of Bible. I own many Bibles, but as of **KJV** or **NKJV** I presently do not own any translation. This is why __I want to get some knowledge about each__ before deciding which one I will get... I have read a [Wiki webpage](http://en.wikipedia.org/wiki/New_King_James_Version) about NKJV, but the results there are not enough, as I'm not about modernized English language. I'm interested for the accuracy to the original scriptures. **What are the differences between _NKJV_ and _KJV_ translations?**