Spinach is one of the BEST sources of Folic Acid. If you don't like spinach try adding a litle to some pasta sauce or eggs. I can't eat the stuff out of the can because it grosses me out but I can handle fresh spinach in a salad, on a sandwhich or "wilted" as the call it when it's cooked into a pasta sauce or eggs.
Breakfast cereals are fortified with Folic Acid. The government mandated this a few years ago.
It's also in many fruits and veggies.
Make sure your prenatal viatamin contains at least 400mcg of Folic Acid and a healthy diet can take care of the rest.