A view form is simply an AR System form that points to an existing SQL table or view.
So, if you already have the table or view in place that you want to expose, just run the development environment (either the Admin Tool if pre 7.5 or Dev Studio if 7.5) and create a new View Form. The system will then ask you for the name of the table to point to and will then show you all the fields of that form that have a compatible data type and allow you to select them and have them added to your form. You just lay out your form, give appropriate properties, and you are good to go.
There is documentation in the manuals around view forms about mapping things like selection and datetime fields and how that is handled and documentation around what DB datatype are supported (if your table has unsupported types you may need to put a DB view over the table coercing the types we don't support into types we do and then build your AR System view table on that view).
I hope this is enough to get you started.
For fields you can either directly take the columns of the table or you can create your own fields and map it to the corresponding columns in the table(provided they are of the same data type).