a few simple things to consider
1. Do you have good suppliers (some require you to have a point of sale i.e a shop where the customer can visit)
2. Are you going to hold any stock (cost/money implication)? or will your supplier deliver direct to your customer? (Bad thing about not holding stock is you cant check the quality therefore returns may be a headache at times)
3. Read about the Long Distance Selling Act 2000
4. Can you build a website?
5. How are you going to acceot payment? ( a few options for online payment but none are that cheap to set up)
6. Company tel and fax numbers? Can people contact you? will they leave a message if your only there part time?