For a while now, we've been involving Ryan more during our mealtimes, showing him (in exaggerated motions) how we chew, letting him see what we're eating, and so on. Once in a while we would bring the spoon to him to see if he's interested. Initially, he wasn't.
Then a couple of weeks back, he started to exhibit a greater interest in our foods -- looking intently at our food and opening his mouth. So we stopped offering him our spoon (no sense in frustrating him because we're clearly not going to feed him what WE are eating) and started to prepare some foods that he can eat. So far we've let him try prune juice, white grape juice, banana, apple, pear, sweet potato (all mashed) and oatmeal. Thinking about it now, that sequence may not have been the best -- some say we should start with bland foods and work up to the sweeter fruits. Some websites also say we should cook the fruits and not offer raw fruits until later. Oops.
Most current literature advises waiting until the baby is 6 months old (he's 4.5 months now) before introducing solids. Mostly because his digestive system isn't ready for solids yet. However, about the same time he started to exhibit an interest in our food, his diapers also started to stink, so I figured some enzymes must have woken up.
I had also let him lick a couple of Ricola sweets, which he liked very much. In fact, when I offered him the second sweet to lick, he *lunged* forward. I think I shouldn't do such things any more.
Initially, he would spit up everything we gave him, whether or not he likes it. He would go through the chewing motions he learned from us, but he hadn't figured out how to swallow. After a few times, he's now much better at it. His current favorite is sweet potato, followed by apple and pear. He likes these foods so much he would lunge for the spoon after tasting the first mouthful, and cry out angrily when (once he has finished) we remove his utensils and bib. And he does finish all of his food. We were feeding him about 2 teaspoons and today we increased it to 4 teaspoons; he finished everything eagerly.