Area of Expertise
It is advisable that you start an internet business in a field of personal expertise. Try to avoid such fields that you are not familiar with or do not have a grip on various matters that will come up during the course of work. Knowing what you are doing is crucial for internet businesses as the audiences that will approach you will probably have searched enough already to know a lot about what they want. If you can give them more options and know your craft, you will have a greater chance of winning their business. After all, internet has a ton of options for the buyers.
There are various channels such as a web store or auction websites. You can even sell through social media pages these days. Ideally have a combination of more than one. This will increase your visibility and people do remember sellers they came across on various platforms.
Storage or JIT
If you are in going to be selling goods, you need to know whether you need to hold inventory or you can procure as you sell using the Just in Time inventory management principle. Generally inventory to some extent will be needed though in some cases, getting the product that sells will be more beneficial. If there is a customised product, you will have to customise it after it sells.
There are various payment options that are available. You can go with reputable sites that take online payments. There are other websites that also offer these services and you can benefit from them as well. If the client trusts you, a bank transfer will do just fine and will also save you from the fees the other services will be charging you.