A good home mortgage service will give you information that is relevant and practical, not what you want to hear. They may tell you that the house is more than you can reasonably afford, this is part of their job as they are there to allow you to pay off the mortgage, not to get into financial troubles that may result in foreclosure.
A reputable home mortgage service will explain both the benefits and the downfalls to a particular mortgage option. They will explain how various types of "no down payment" and "interest only" mortgages can affect the long term cost of the house and monthly payments.
The mortgage company should provide both written and verbal information on the difference between adjustable rate mortgages (ARMs), fixed rate mortgage and balloon mortgages and how each will play out over the time that you take out the mortgage.
