Hi there, and welcome to our forum.
I am not only the founder of the NurseServer Network, www.nurseserver.com , but I also work in an ICU.
For the most part, you will not need any formal education, per se, but will most likely have to take a critical care course which should be offered by the hospital or unit where you decide to work. Then you will most likely be required to work through an internship. Some units require a certain amount of med-surg or related experience.
After you have spent some time as a critical care nurse, you may want to advance your career and sit for the CCRN certification exam... but that is down the road a bit for you right now.
Check out: http://www.critical-care-nurse.org/ or you can find books on critical care nursing by going to the NurseServer home page, www.nurseserver.com , and clicking on the NurseServer/Amazon Shops link in the left hand table.
Feel free to contact me by private message, or come back and post here at the forum.
Good luck,
TracyR