There is quite a bit of equipment required for a full service office, and space is usually the ultimate requirement.  While it's lovely having a single room or area that can accomodate all of the equipment, most residences to not have the required space in a single area to share with your business equipment.  Establishing work areas and stations often conflict with other family member areas and can arise in domestic disputes, so select your work space cautiously.

Customer parking may be prohibited in your residential area, and some locations do not permit home-based businesses.  Know the laws that govern your area before you engage in business, this will prevent any complications from arising that you are not prepared to face or were unaware of.  A quick call to your local city hall should be all that's required to confirm whether or not your venture is permitted.  You might have to register with taxation or licencing departments, be certain you have all the required permits and licences in place before you commence.

Do some investigation before you invest in equipment.  Are there other desktop publishers in your area, and if so how many?  What services do they offer and what are their prices?  Who is your local stationery supply outlet, is it retail or wholesale, do they have minimum purchase requirements, etc?  Taking a step back and looking at the broader picture is useful in determining whether or not your venture has the potential to be successful - where there are several active and established desktop publishers, you might have to find a unique angle or niche, or abandon your plans for your business.