What is the purpose of having so many similar variable types, for example integers and longs?
The purpose to having so many variable types is to help developers, such as you, better manage resources. You should always pick the smallest number possible of variable types that can handle the needs of your application.
What do I do if I want to create a function that alters the parameters passed to it, but doesn't return a value?
The first part of the answer is to declare your parameters as either ByRef in Visual Basic or ref in C#. The second part of the answer, creating a function that returns nothing, can be done in Visual Basic by using a subroutine instead of a function. In C#, you would still use a function, but you would declare it as returning type VOID.
I need to create an XML Web service that will alter information about an appliance being serviced. The information will include the owner name, the date, and a status. I would like to return all of this information to the client application in one method. How can I do this?
Create a class based on your application and give it all the attributes that you need to pass back to the client. Then, simply create your method and have it return the class you created.