melissa, only you can judge if your son is ready, just don't feel pressured to do it because others are or say he should be!
i just potty trained my daughter. it took two weeks before i could confidently say she was done. i thought that was pretty good! and, i was surprised that she was night trained too. i expected her to wear diapers for much longer. it's like their bodies and brains just "click".
i read Becoming Toddlerwise by Gary Ezzo. It's a series. I always liked this series, which starts with Becoming Babywise. They also have a book specifically about Potty Training, called Becoming Pottywise, but I felt that the Toddler version offered enough info.
I got all geared up for potty training, got all the equipment, including a doll that pees, and demonstrated for my daughter how the doll would drink, then pee on the potty (then flush and wash her hands!) and then the doll got a reward! The book tells you to emphasize the goal of "staying dry". when the doll got a reward, my daughter wanted to get into her underpants too! we stayed in a tiled portion of our house for a few days (was very trying). at first, she had LOTS of accidents! I thought, is she not ready? but i kept with it. a friend told me that her method said to just put them on the potty when they would start going, and if they got anything in the potty, they get a reward. i would ask her to check her pants every once in a while to see if she was still clean and dry, and then she would get a reward too. the reward was small... one m&m, two if she went on the potty. keep it small, you'll be rewarding often. the trick is -- NO DIAPERS, NO PULL UPS!. once you start you have to stick with it, so make sure you don't have any plans for several days. after a few days, my daughter was telling me she had to go. i had to ask her a MILLION times at first, and i could see that she had to go, but soon she was telling me.
Becoming Toddlerwise said to put the child on teh potty at regular intervals, but my daughter did NOT like being asked to sit when she didn't have to go, so I liked the method of waiting til she had to go. it think it helps them to recognize when they have to go, rather than coincidentally going because they are sitting there.
one more thing...the more he has to go, the more practice he has, so load him up with yummy drinks like juice, choc milk (it's only for a few days).
this was a very difficult few weeks for us, just because of staying home so much and it being so much time spent in one place but it was worth it! just remember to make it fun, and exciting with no struggles! let him pick out his own underpants and talk it up for a few days before starting.
good luck!