Here are some questions to consider before you build your ecommerce site:

1. What type of products are you going to sell? Are any products digital? Are you seeling wholeslae? Do you offer discounts or coupons?
2. How are you going to take payment? (payment gateway, currency)
3. Where are you going to host the site?
4. How many products are you planning to carry? Do you already have the products listed somewhere? Do you require bulk uploading? Are there various product configurations? (colors, sizes, models, options)
5. How are you going to brand your new store? You brand image should follow through on all aspects of your business, logo, colors, design, customer service policies and even your auto responder correspondence.