In Animal Farm, when (what chapter) does Napoleon take the puppies, and is there another way that Napoleon has power over the other animals?

Napoleon takes the puppies of Jessie and Bluebell very
early in the book - section three. This shows that Napoleon right from the beginning was
thinking about how to gain power. This is an important point to bear in mind, because he
was more scheming than Snowball and any other animal for that matter. Here is the
text:

It
happened that Jessie and Bluebell had both whelped soon after the hay harvest, giving
birth between them to nine sturdy puppies. As soon as they were weaned, Napoleon took
them away from their mothers, saying that he would make himself responsible for their
education. He took them up into a loft which could only be reached by a ladder from the
harness-room, and there kept them in such seclusion that the rest of the farm soon
forgot their existence.

Now
as for your second question, there were many other ways in which Napoleon sought to gain
and maintain power. First, he used rhetoric. He had Squealer who would always spin
things to his favor. Also because Squealer was such a great speaker, he persuaded the
animals that he was always right. In fact, this was one of Boxer's
mottos. 

Second, he limited the education to pigs so the
other animal could not read. If knowledge is power, than he had all of it. This is why
none of the animals could really create any type of revolution. The only one that could
have was driven out - Snowball. 

Finally, when Napoleon had
things in place, he could do whatever he wanted. At the end of the book, he turned into
a human and the animals did nothing, because they could do nothing - so complete was his
power.