Ok after reading all the other posts i am going to have to disagree with them all. Yes iron is important to your baby but cereal is not the only place for them to get this. Veggies & of course meats (red meats has more) have iron as well (green beans, peas, potatoes, avocado, pumpkin...) Berries & grapes (peeled of course)are also a good source of iron. One he is older raisins are also very good for iron.
Another reason to hold off on cereal is that a child's digestive tract really cannot handle grains that well until after 10-12 months. Most of it passes right through & does not get digested. Plus the longer you hold off on offering grains the less likely they will will have allergies or sensitivites to them later in life. Plus rice ceareal can be constipating for some children. Cereal is genereally offered as a first food because it is tradition. However new studies are challenging this and many pediatrtions as tellign parents to wait longer. Utlimately it is your choice.
If you do decide to offer the cereal try mixing it with the veggies & fruits for more flavor & of course to get the nutirents from them as well. Plus the sooner you get them eating a variety of veggies & fruit the more likely they will enjoy & continue to eat them later.
Some of the best first foods are sweet potatoes, banans (as long as they don't get constipated) apples, squash (includign pumpkin), carrots & avocado.