I dont know what it is like there to apply , but all i will say is make it that your application is the absolute best that it can be so that you are the only one considered , and good luck dont stress if it doesnt happen first time and just keep on keeping on you will get there if you really want it ...
Practice interview questions so you don't freeze on the spot. Learn all about the dept you are applying to. Make your resume as perfect as you can( as already mentioned) Make multiple copies of your resume. Run.......then do more running and when you're done that...run some more.
Eat healthy and exercise. Be early for every interview and testing.
Don't give up.....no matter what!!!!!