That looks okay (it's a bridge circuit) but what happened to the op amps?

 

I was lazy with the drawing. But they'd go where the batteries are. what number op amps and mosfets should I look for? I'm planning on going to Fry's later today.

 

I picked up an nte 948 for the op amp and nte2987 for the n channel MOSFETs. The op amp seems to work haven't tried the mosfet though

 

This is kind of unrelated but I'm completely lost on how exactly a mosfet is able to supply more current to drain than it receives from source, can someone explain the physics?

 

This is kind of unrelated but I'm completely lost on how exactly a mosfet is able to supply more current to drain than it receives from source, can someone explain the physics?

Who told you that??
The drain and source current are identical since there is not other place for the current to go.

 

That makes sense, but now I don't see how mosfets help me at all...

 

Can an nte948 op amp output 500mA? If it can I think Everything will work fine... I guess not, data sheet says only 25 for a short circuit . If I wire all 4 outputs together does that value add linearly to 100?

 

The NTE948 is basically a quad 741 opamp; and it's maximum output short-circuit current is 25mA.
Datasheet: http://www.nteinc.com/specs/900to999/pdf/nte948.pdf

You need at least 20 times that much current.

Take a look at the L272. STMicroelectronics' datasheet for their L272:
http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00000054.pdf

Look at Figure 9, "Bidirectional DC Motor Control with mP Compatible Inputs" on page 5. Note that Vs1/2 can be simply a resistive voltage divider across your logic power supply; and that your Vs2, the opamp supply voltage, must be greater than or equal to the logic supply voltage; otherwise the inputs might be damaged.
This opamp is just what you need, and it's widely used in the automotive industry. You need to supply the L272 with about 1.5v more than your motor requires, as the L272 can't output within about 0.75v of either power "rail".

Digikey carries a Fairchild version for $0.66 USD each:
http://www.digikey.com/product-detail/en/L272AM/L272AM-ND/1053997
If you're going to need more than a few, you might want to consider buying from Arrow:
http://components.arrow.com/part/detail/41922434S7860191N7769
50 of these will only set you back about $10.54; plus shipping.