@compiler_guy: the average acceptance rates are about 5-10 students per year per department, that represents anywhere from 1% to 6% of applications. I don't know hard numbers but that's what I see come in every year and those are the rough percentages I hear about.
@ChristN: Most universities have very good job pages you can search. There are tons of jobs that can help you get research experience. Also internships are really good ways to start. Getting into a university on a job is different, you need relevant work or educational experience, but since the pay can be low you might have a better chance to get in because a lot of people go for industry jobs that pay better.