Voltage Amplifier using Op Amp 741
An op-amp is a building block of a working amplifier.  It's not what you want in and of itself.

Here's the short story:


Use two 9V batteries, for a +9V supply and a -9V supply.  You don't have to run "ground" to the op-amp, although you can, depending on the circuit.
Read this page.  I can't recommend it very strongly -- it's in the top five things that popped up when I searched for "differential amplifier".  But it should give you some guidance about what to do with your op-amp in the circuit.
Using a 741 op-amp is like using a Model T Ford.  They're interesting antiques, nice to have in a museum, but you wouldn't want to use one every day.  There are much better op-amps these days.  There were much better op-amps 30 years ago.  I doubt that 741's are finding their way into new designs by anyone other than hobbyists.