So I'd like to construct a simple sample and hold circuit using an LF398, 9 vdc battery as the supply and the input will be from a photo cell with a 30 ms minimum response time. Could someone review this schematic and check my work? Thanks in advance.

 

It is dual supply, it seems to me. You will need two 9 volt batteries. One for +9 volt, one for -9 volt. Like this: http://forum.allaboutcircuits.com/picture.php?albumid=159&pictureid=1967