DataSet and GridView

I'm sure this is a very easy thing, but I can't seem to find the write
help on the web...

I have a dataset going into a Gridview. Instead of having VS 2005 do
everything, I want to 'hand code it', since I have modifications to
make. My GridView automatically opens up in 'insert' mode, and I
simply wish to enter information into the open field, press a button
which updates the DataSet, and adds a new empty row right below the one
I just edited. I want to be able to leave all rows open for either
editing or (the last row) to insert a new record. Rather easy. I can
create the dataset and attach it to the GridView, but how do I take the
information from the Grid View and transfer it into the DataSet?

Any help (in VB) would GREATLY be appreciated!