Some question for creating online shopping?

Newbie in online shopping need some help?
i'm 18 this year, and i plan to start off my little business using online shopping through using buy and sell method. but i need some helps in this,

1) any other method can use to earn money other than using buy and sell?
2) is there any other ways can make my customers trust me when it is a new online shopping web?
3) if i deliver the items to my customers(the address everything is correct), but they lie and tell me that they never receive(assume that they already receive the items), and want the fund back. what can i do?

if possible, provide some useful website about helps/tips for newbie creating online shopping web

To start out with you best bet is to start off using ebay to buy and sell your items, till you get a good amount of regular customers and get more experience. This will also protect you a little better against customer who try and say they haven't recieved there items. But still evne using ebay you will need to keep reciepts from the post office just incase they try it on! the best way to gain trust is to be truthful about how long it will take to send the item, what condition the item is in and only charge resonable postage - your not out to make money from the postal charges. Be truthful and people will trust you, also you could offer a loyality scheme, come back and get 10% off or something like that. And try to keep to a certain few items, don't try and sell a lot of different stuff, keep things to clothes or book, rather then selling pet stuff and home electricals. People are more likely to bu from you if you seem to have a knowledge about what you sell, people buy from Dell because they have that special knowledge of dell computers. keep it simple!