For starters, try one food for 4-7 days before moving on to another. Such as, squash for 4 days, then try something else. Also, if your baby doesn't like something the first time, keep giving it to them. This is all new to them, so they may not like it the first time around. With my daughter, my ped suggested starting with cereal, then moving on to yellow fruits and veggies, then the green. The green (peas, spinach, etc.) tend to cause more gas that younger digestive systems can't tolerate yet. I started both of my kids on squash, then bananas, then carrots, etc. I alternated fruits and veggies so that once they had a few of each, I could give a fruit in the morning and a veggie at dinner. Right now my son who is 5 1/2 mos is on prunes. So, we have prunes and cereal for breakfast, and a veggie that he's already had (like sweet potatoes) and cereal for dinner. My ped said to wait until at least 6 mos. before starting meats. With my daughter it became a balancing act with which fruit to give with which veggie. Some veggies like squash made her slightly constipated, so I'd pair that with pears to help loosen her stools. Also, she couldn't eat anything apple until after she was a year old because it gave her horrible gas pains. She also spit up, but it wasn't very much and it was basically with all foods so I just continued with everything. You'll get a lot of advice, so just pick the one that sounds like what you're comfortable with and go with it. Good luck!