One type of home business that you need to beware of are often called "Gifting Programs". While these programs vary significantly, they generally involve receiving tax receipts for your initial "gift" (or investment), and you can also earn money by referring others and helping them "give" money. These companies are (almost ?) always illegal.
A recent version in Canada involved a company which gave tax receipts for much larger amounts than the donations that were given.
You can read the story:
Whatever the case, beware of these "opportunities" that makes "giving" sound like it can make you a profit.