I have 3 and I've always tried to follow the lead of the baby when it came to food. There were a few patterns I followed though for feeding...
1 - I typically offered water in a sippy cup with meals from the time they started eating. They wouldn't drink much, but it was more for getting familiar with the sippy cup and learning to use it. They aren't supposed to have a lot of water still at that age, but the few sips they get is fine.
2 - I would usually end up nursing in between meals instead of at meals.
3 - Once they allergy tested more foods, I typically offered a fruit and cereal for breakfast, fruit and veggie for lunch and veggie and cereal for dinner. We're vegetarian so we didn't incorporate meats. Since I only nursed, cereal was important for iron after 6 months so we always tried to do that 2 times a day. Plus it's filling.
4 - As their meals increase, you should notice a natural decrease in the bottles. He simply shouldn't be as hungry. Once they got onto enough foods to do the above eating pattern, I'd still nurse in the am and nap and bedtime. The other times fell first for us as they were less emotionally attached to them and just weren't as hungry. If they weren't feeling well or got hurt they might want to have an extra nursing session, but in general it fell to basically 3 times a day. Try to watch him closely you might see that he's giving you subtle clues about being more or less hungry. Kids are really good at knowing how much they need to eat. If we follow their lead, it helps them to keep that sense and reduce the chance of them developing eating problems later in life. Some days he might be more or less hungry than others and that is ok. It all evens out and activity level will influence it too.