How does one built credit without having a credit card, house, etc? Does it help to have a secured credit card?

The best advice I have for you is to start small -- an unsecured credit card is one way. Another way is a department store charge card.

One of the easiest is to ask a relative (a parent for example) to co-sign for you to get a small-balance department store charge card (Sears or Dillards are good). Buy something modest and then pay it off ahead of time. Be religious about making payments on time.

Pretty soon, you will have a credit history and be able to get a loan in your own name with a co-signer.

Credit is nice but be very careful. Credit is a trap that can swallow you up. You best best is to pay cash.