In addition to breast milk or formula, baby can start solids around 4-6 months. Every baby is different, so make sure to talk to your pediatrician before starting.
Here is a basic guideline:
4 months: Start rice cereal and then oat cereal - rice cereal is easier to digest. Mix it with a lot of water, formula or breast milk at first, so that it is very runny. Don't be surprised if baby isn't into it at first. It took me 4 tries over 10 days before my son would eat it. They are getting used to eating sitting up, the texture and they might still have a reflex that forces their tongue to sort of spit out the cereal.
6 months: Stage 1 baby food - this food is pureed so it is very watery and easy for baby to eat. Try veggies first and start with squash, carrots and sweet potatoes. Follow those by green beans and peas. You can also try making your own, particularly if you want to try unique things like edamame or avocados. I tried both of those and my son was not interested. In fact, he dry heaved and gagged!
Move on to fruits next. No particular order seems to matter. My doctor said to leave a full week in between each food. But after 7 weeks and he still hadn't tried a fruit, I went down to 3-5 days between each. If you have allergies in your family, a week might be a good idea.
7-8 months: Stage 2 baby food - you can definitely try this earlier if you want. Stage 2 is strained which is a little teeny tiny bit lumpy.
8-9 months: Mashed foods and some finer foods like pieces of bagel, toast, pasta and cheese.
10-12 months: Finger foods and easy to eat table food - banana pieces, soft cheeses, pasta rings, etc.
I have noticed that there are all kinds of different beliefs on when to move on to the next level of foods. I think it really depends on your comfort level and your baby. You will notice that some items (like Gerber Star Puffs or Zwieback crackers) will have guidelines to follow. One interesting thing to keep in mind is that a baby does not need teeth to progress to less pureed foods. They have incredibly strong jaws and can gnaw on things. BUT, remember, that choking is always a hazard. Use your instincts and remember, you don't have to rush it. Have you ever seen a three-year-old eating strained green beans? No chance!
-set of plastic bowls - there are some that have a divider down the middle, so you can put cereal in one side and a veggie in the other
-set of rubber or plastic spoons - metal can hurt their sensitive gums
-sippie cup - you can try this at about 6 months, so you might as well buy it now (try one with handles and either a rubber spout (similar to a nipple) or one with a straw
As you set out on this adventure, keep remembering one of my mantras. GO WITH THE FLOW! Nothing is easy with a baby. But everything is just a phase.