There are 3 areas to consider:
Immigration
As a Dependant Visa holder you can be employed or carry on any business without further paperwork. (Although note that your husband may only work for the company sponsoring his Employment Visa - he may not do any additional work for your your business.)
Business Registration & Tax (Inland Revenue)
If you're carrying on a business then you need to register it as a business:
Businesses Registration The Property / Lease
Whether you can carry on a business in your home will depend on the terms of the lease. Generally these specify that the property may be used only as a residential dwelling, so strictly you can't. However, if your business is largely computer / paper based and doesn't involve making anything on site or moving large amounts of stock in and out then I really don't see that this would be a problem.