Take your feeding cues from your baby. If he's fussy, stop; if he's interested, keep going :)
I introduced new foods every 3 or 4 days, starting with root veggies, lentils and stuff like avacados, bananas, apples, etc. I also kept up with the previous foods I'd introduced, mixing up the 'menu' and usually giving 2 foods per meal. You could just stop the cereal, but if it's iron fortified, you may want to keep it up until baby is eating other iron-rich foods. Start with just a bit of the new food and follow it up with a previous food. Again, take cues from your baby. If he's interested, keep going.
The only time I gave my girls water before 12 months (I was exclusively breastfeeding) was during their solid-food meals. I boiled some water, cooled it and put it in a sippy cup. They needed help for the first few months and I don't think they actually drank all that much, BUT they were never on bottles because once they were weaned at a year they were quite proficient with the sippy.