We started at about 5 months and worked our way up from the least desirable foods (peas, green beans) and then better tasting veggies (squash, carrots, sweet potato) and then finally, fruits (pears, applesauce, prunes). All this was over about a 1.5-2 month time period. Our pediatrician advised us to work from less tasty (green veggies) to sweeter with the logic being that if you start them on sweeter foods, then it would be much harder for them to accept eating those peas and beans. Personally, I am planning on skipping those all together with DD2 who is 2.5 months. My DD1 never ate the green veggies as baby food, but absolutely loves veggies now.