how does the Earth's rotation affect human life?

Definitely positive. If the earth didn't have a sidereal rotation, day and night would be so long that the days would burn everything up and the nights would freeze everything. Plant life would most likely be impossible. Higher life forms would never have evolved.

If the earth didn't have a solar oriented rotation, (permanent day on one side and permanent night on the other), the situation would be even worse.

Gravity is not an issue.

The centrifugal force is minimal, however the passing of day and night is caused by the Earth's rotation. Seasons of the year are caused by the tilt in the Earth's axis relative to the sun. When the northern hemisphere is toward the sun it is summer there and winter in the southern hemisphere. 6 Months later the Earth is halfway through it's orbit around the sun and like a gyroscope the axis is still pointed in the same direction. Now it is winter in the north and summer in the south.

Positive...

http://starryskies.com/articles/2003/09/earth.rota...

Just off the top of my head:

We would be confined to a very small portion of the Earth's surface without the rotation. We would not live on the Dark side because it would get to cold and the light side would be mostly desert. (this alone would probably cause the human race and all other life on Earth to go extinct)

I believe the effect of gravity would be greater also due to the lack of centrifugal force.

in no way by any ability. Mega Earthquakes will proceed to take place. it quite is unlike each and each quake slows the earth's rotation. some sluggish the earth's rotation, some speed it up.

Um, if it didn't rotate then one side would always be exposed to the sun and would never cool, and the other side would get NO sunshine, would be eternally frigid and nothing would grow. I'll leave it to you to decide if that qualifies as 'affecting human life' and whether or not it's positive.

It causes day and night, as the other person said. Without the Earth having a tilt, there would be no seasonal variations, so we are lucky Earth has a tilt. I would think of it as a positive.

Well, it gives us day and night, for one thing. Tides, too.

Edit: If the Earth didn't rotate, it would NOT have one side facing the sun at all times. For that to be the case, its rotational period would have to equal its orbital period - like our moon.

Also, in fairness, I should amend my original response to specify that it wouldn't do away with day and night altogether, it would just increase the day-night cycle to a year.

If the world didn't rotate, the world would probably be uninhabitable, one side would be forever in darkness, so no plant or animal life. The side continuously facing the sun would bake.

It effects all life in one way or another, either directly or indirectly.