Is online shopping for me?

I suddenly realized that next month is September already. That means, Christmas is just around the corner. It isn't a wonder that people are starting to shop for gifts already. It is after all advisable to do Christmas shopping little by little so one wouldn't be so shocked at the expenses. I probably should get started on my list very soon. I also need to decide where I would shop. One option is online, where I could get my family and friends some custom t-shirts, custom jewelry or accessories and other novelty items. If one of my friends feels strongly about the great disaster that BP caused, I could get BP oil spill t-shirts for him or her. There sure are a lot of interesting items online. And, I could do shopping from the comfort of my home. I just have to wait for the items to arrive. I want to give it a try. The truth is, I have never tried shopping online. I have second thoughts about it since I couldn't see the actual merchandise. I am also not so sure about the sizing. What if it doesn't fit? I couldn't use it when I need it because I have to ship it back for an exchange. Do sellers even have this kind of service? What about the shipping charges? And the materials used? That means I have to really trust the seller. There's so much to consider. I will have to seek the advice of people who are expert online shoppers.