Have you already completed your CCSP (CCNP Security)? If so a lot of the material you used to study for that should help for your preperation towards the CCIE Security V3.0 written. Personally I used the CCIE Network Security Technologies and Solutions book to prep for my written but I had already gone through a number of other books during my CCSP track. Here are the two most critical books I would recommend purchasing:
Hands on experience will help you a lot, but the written exam contain a lot of theory and concepts, most of them you may have worked with, but you should be familiar with the terminology, best practices.
I used all the 5 CCSP cisco press and dominate all the theory, and still had to go over the CCNP material. INE VOD, Google.
There is a long way towards the CCIE, but if you put efforts you will get there.
Best of luck
I am studying for the written as well. As I study, I am posting resources to assist other students.
Here is the first in a bunch of posts that I have already completed for you and others:
The following google search criteria can help you find the other posts easily:
site:blog.ipexpert.com ccie security written
Enjoy your studies - I know that I sure am!
It might be better to wait for the v4 written exam as it due to be release soon, my reason for saying so is when Cisco release v4 you may only have 6 months to study for, and pass the v3 written and lab exams. Based on my own experience it took 3 months studying for the written and another 12months for my 1st lab attempt back in January, 2nd attempt next week.
I'm sure there will be alot of overlap between v3 and v4 but but if you study for and pass your v3 written, and then in 6-8 months time when Cisco stop the labs for v3 (not sure how long v3 labs will be available when v4 is release), will your v3 written allow you to take the v4 exam?
It would be nice studying for your v3 written and then having to do your v4 written.
I would recommend you use the Network Security Technologies And Solutions book by Yusuf. Additionally, he has flash cards that go along with that for an extra cost that are worth it. With those two things and some hard study I think that should prepare you. That is what I personally did. Good luck.