Assets = Liabilities + Share holder's equity
That is true from an accounting standpoint but does not tell you what a business is worth.
Here are the 2 easiest approaches for "non finance people"
1) Value at a future date of selling the business divided by perceived risk.
Steps: A) figure out what the perceived absolute maximum value your business is worth in 5 years. B) determine the perceived percentage chance of that happening C) multiple by that percentage. D) discount by risk free rate (this will be over many, many people's heads, but it is the risk free rate because the "risk" is built in to the percentage) E) that is the max value.
* Improve the perceived future value or the perceived percentage chance of success or decrease the estimated risk free rate and you will increase your current value dramatically.
2) Use an NPV model to determine the value of your business. This is not a good way to go for VC funding