Re: Almost-4-year-old WILL NOT LISTEN!
Personally, I found 4 to be the hardest age of all with my 2 boys. I've often said that I think it's the most under-rated age there is. They seem to go through all the tanturms/willfullness that 2 year olds do, but at this age, they know exactly what they're doing.
A book that I found to be extremely helpful is called "SOS! Help For Parents" by Lynn Clark, PhD. Last I checked you could buy it online.
One aside - I don't think that a not quite 4-yr-old is capable of cleaning up a room without help. I wouldn't have a power struggle over that one. Instead, I'd make it a game. Set a timer and see if you and he together can "beat the clock" in cleaning up the room. As long as he is helping, it doesn't matter if you're doing most of the work. If he goes for that, then try a new one - see how many things he can pick up in a minute. However many he picks up, he WINS!! (they love this!) Then see if he can beat his record.