Basically, any money you put into the business with personal funds is a loan into the business to be paid back. Lets say you put in $10. At the end of the year you profit $100 dollars. That $100 goes back to you as owner, however only $90 of it is considered taxable money since the 10 is just a payback of the loan.

That's the simplified version, assuming you're an LLC or S-Corp. Talk to an accountant to get advice relevant specifically to you.