I breastfed both of my daughters and they gained weight very quickly for the first 6 months. For example, when I took my 2nd daughter to the pediatrician for her first checkup after the hospital 4 days later, she was back at her birth weight! Usually that is hoped for when your baby is 2 weeks old and why you go for another checkup then. Needless to say, we didn't have to go for that visit! My 3 month old babies were the size of 6 month old babies. But that started to slow and by 12 mos. they were average. Every baby is different and you have to do what you think is best. I didn't worry about overfeeding them while breastfeeding. Your milk is made especially to meet your baby's needs, and adjusts accordingly. I just looked at it as nature's way of making sure I had a strong and healthy baby.
I also made my own baby food and used the book "Super Baby Food" by Ruth Yarin.
http://www.earlytolearn.com/2009/reviews/books/super-baby-food/ I loved the page where she gives you an idea on what foods are appropriate for each month. I firmly believe both of my daughters are such good eaters (meaning not picky eaters) because they have had 'real' food from the beginning and have always just eaten what we are having for dinner too.