I used the Rita Mulcahey book and test software. It's a ah heck of a test and yes they expect you to have quite a bit of actual PM experience before you take it. I took it before the latest version came out in September last year. At the time you needed 4500 hours of experience (with a college degree) and I think 7000 hours without. It may be different now but you'll have to look that up. You have to document that experience and I know someone who was audited.
Questions on the test are set up to trick the folks who only marginally studied. Its multiple choice and in some cases all the answers can be right but you have to pick the best one.
I've talked to some people who read the PMBOK 6 times and passed it. I've talked to a number of people who have taken and failed the test the first time because they didn't study.
What you need to think about is that once you pass, you still have to work to keep the certification. That involves obtaining 60 PDU's over the following three years of certification. Info about this can be found on the PMI website mentioned earlier. Point is, don't bother taking the test unless you really want to be a Project Manager.
Good Luck