hi ayne,
The LM324 is designed specifically to work from a single supply rail.
Also the TS358 dual opa [25pence UK] will accept common mode input signals to Vee/Gnd.
If you are considering any serious work with opa's, low level dc in particular, I would recommend a dual rail supply.
Some of the 'ac' opa circuits with potential divider offsets have some poor features, in particular power rail noise and changes in the gain/frequency performance. To overcome this, additional components, zeners, caps and the like are required.
Its much easier to generate a negative rail voltage.
Regards
EricG