Marshall Brain knows how stuff works.

Marshall Brain
While many of us have trouble working our VCRs, Marshall Brain (yes, that is his real name!) makes a living figuring out how stuff works. In fact, he wrote the book— Marshall Brain's How Stuff Works !—and created the popular website, HowStuffWorks.com.

Marshall Brain explains how e-mail works, and more.
Maria Bartiromo knows money.

Maria Bartiromo
CNBC star Maria Bartiromo is the host and managing editor of the nationally syndicated Wall Street Journal Report as well as the anchor of Closing Bell . She also writes a financial column for Business Week as well as Reader's Digest .

Money 101 with Maria
Our resident expert, Oprah herself!

Oprah
The tables have turned! Oprah answers viewers' questions.