This having been said, don't be afraid of email. It is your friend and the best way to communicate with others on the net regardless of the method used to get it. You never know who you are communicating with on the net and who is listening. Unless you absolutely must, don't give out your real name, address, phone number or any other details that you would not like the rest of the world to thumb through. Don't give out your email address to every web site that asks for it or you'll have nothing but junk mail in your mail box until the cows come home.
Credit cards are to be avoided if possible.
Never email credit card details to someone . The 's' in the former stands for secure. As with any cross-section of people, there are bad eggs and good eggs, the internet allows the bad eggs to contact you without you being able to look into their eyes and see they are bad. You should never tell anyone your dial in or email password as this can enable them to use time and cost you money. An even worse outcome may be that they log in as you and perform illegal or malicious acts in your name.