The first step is the gateway to all Census jobs: Taking the test. Although a surprising (alarming) number of people don't pass, it is the easiest test you can ever imagine. Its most difficult concepts include reading a map, alphabetizing and understanding what a "block" classification is. Study materials are available before the test if needed!
Once you pass this test (you learn of your results the same day), you can re-take it if you are not happy with your score. The Census does not penalize you for taking it more than once.
At a later date, you will unexpectedly receive a phone call and request for a phone interview. Although some interviews are set up for a later date, most proceed directly after you pick up the call, with the "interviewer" reading ever-so-distinctively from a cue card. After reading a verbatim description of the job, she will ask you whether this job interests you. "Yes" is the response that gets to past this question and through most of the rest of them. Variations include "Yes, yes, I do." "Yes, Yes, I am."
The only part that might throw one off is the Spanish language portion. Depending on the job, when they want some Spanish-speaking ability (and for most jobs it really is not even necessary), they may ask you to tell them when you last spoke Spanish -- asked, and to be answered, in Spanish.
When you hear whether you got the job varies. It could be the next few days or week. If you're rejected, your file will be kept on record to be considered for the next job opening. It remains a mystery as to how you are selected for certain positions. The usual premise is your home's proximity to the job location and how high you scored on the test, but depending how they sort the application, these things can be skewed measures.