E-Commerce implementation

1. What is the SDLC approach to building an e-commerce site?
2. What are the functionalities that an e-commerce site should deliver?
3. What are the decisions to be made when building an e-commerce site?
4. What are the software needed to operate an e-commerce site?
5. What are the factors affecting the performance of an e-commerce site?
6. What are the factors in successful website design?