Published: May 01, 2010 3:15 PM EDT

NEW YORK (AP)- Saturday is the day that the door-to-door part of the latest census gets going.

It sounds simple enough. Knock on some doors, ask some questions, get some answers. But it's not that easy.

For one thing, there are 48 million addresses to check.

More than 600,000 have spent most the last week getting trained in all the things they need to know to get the job done, from how to deal with people who are reluctant to answer to what to do at homes with guard dogs.

They could face a number of scenarios from people not being home to not speaking English to not wanting to answer any questions.

Census workers have been trained to deal with those situations.

They've also been given some practical advice: Wear comfortable shoes.