Dont mess with volts, I tell you. You will never win. And in this case, we need to get from the 9, the battery, all the way down to 3.3 or so. Just look at the data sheet (page 1) which says our 24F16 chip can't tolerate more than 3.8 volts.
So lets bring in a 1117 3.3 voltage regulator.
IMPORTANT NOTE; do not mix up the pin labels in the schematic with that of the actual physical pins! things will get too hot too soon... this is all in the data sheet for the LM117.
Pin 1 goes to ground
Pin 2 supplies the whole board with 3.3 volts.
Pin 3 is the raw 9 volts coming from the battery.
This is great but we need to smooth it out, since any spikes of power could create havoc. We do this by using capacitors to keep the Current Continuously Consistent. The three big C's. Thats what decoupling essentially boils down to (at least for us).
With this pair, we get a smooth sail throughout the whole board. With this setup, I found a 10uF cap on power in and power out pins works wonders. Now these are polarized, so make sure the back strip leg always heads towards ground.
Now its time to check the current supply for the whole board. If there are any issues, best we work them out before adding (and, perhaps, frying) our microcontroller. The reading should be somewhere around 3.3 volts.