How are call options different from put options and when to use them in markets?

What are the different ways in which I can use options for trading in the markets?

I am planning to sell some call and put options. Are there any risks in it?

Are options really useful in playing uncertain markets?

How are futures different in concept from options?

What are different pricing models that are used for options valuation?

What are the benefits of dealing in options; both calls and puts?

What are the practical uses of index options and who are the users typically?

What happens to the value of the call and put options under Black & Scholes when the interest rates in the economy move down due to RBI repo rate cut?

What happens to the value of the call and put options under Black & Scholes when the dividend yields on the index move down due to a cut in the dividend rates?

I am planning to start options trader more as a buyer of calls and puts. Are there some basic things that I must remember?