This whole thing is very similar to sample proportions. In fact, all properties are the same. The only difference is the formulas. Standard deviation is equal to sigma over the square root of teh sample size as long as the population is ten times the size of the sample.
Also, there are two important ideas the grasp. The first is the central limit theorem that states that the standard deviation given before is that of any sufficiently large population. The law of large numbers states that the observed mean must approach the true mean mu as long as the number of observations approach the population size.