I haven't noticed any foods that have bothered my baby, and I eat a lot that are supposed to be irritating (beans, fruits, veggies, chocolate, soy, dairy). It just seems like everything good for you might be trouble, so I just eat it and pay attention to changes in her temperament.
I wanted to add my encouragement to give bfing a shot and sticking with it. It was really hard at first because my supply was inadequate so the baby didn't gain any weight for about two weeks. We had to supplement with formula using an eyedropper to avoid nipple confusion (not easy!). Add to that the usual pain associated with the beginning of bfing and I was pretty miserable. But now (11 weeks) it's just great. In fact, I would do it even if there weren't health benefits because it's really easy and convenient, and also because it's incredibly effective for soothing my very fussy baby. I have no idea how I would handle her if I wasn't nursing her. It's the only trick that ALWAYS works. In fact, sometimes I worry that I'm creating bad habits but hey, parenthood is survival, right?