L.S.
I think after 6 months or so it's safe to introduce water. Check with your ped though. It has something to do with their kidneys not be able to handle water until a certain age. I found prune juice (diluted) to work wonders when we introduced food.
I bf'd and my son didn't become interested in solids until 7 months. I found prune juice (diluted) and pureed prunes to be really helpful. Commercial cereals can have a lot of iron which constipates. Don't get too hung up on the cereal thing either. YOu can give fruits and veggies. Remember, food is just an experiment the first year. Your baby should be getting the bulk of her nutrition from you. You're smart to take it slow and easy. My inlaws thought I was nuts but you know what? My son has no food sensitivities and is a really good eater even though he started about 4 months later than his cousin (who now has food sensitivities and eating issues).
I'd recommend the book, Super Baby Foods. The author's a little over the top on some things but it's a great reference of what foods to introduce and when. I actually had a lot of fun making baby foods and it wasn't hard at all. I even made him his own cereals that he liked a lot more. (He absolutely hated rice cereal).
Dont' be surprised if there's gas. My guy was gassy anyway. Maybe it was from my diet. The poo also get's more interesting too but nothing that really bothered me. I think my son was constipated from time to time so the prunes were good for him.
Good luck and have fun!