Setting up a blog has a lot of little parts but they are fairly easy if you take it slow and read the instructions Tiny zone. Most blogs nowadays have ready-made templates. The template is the background look of your blog. Templates range from the very simple blue band at the top to some that have flash components (not recommended because many people are on very slow internet services).
Once you sign up for a blog, you will have a myriad of choices. Don’t let the choices overwhelm you; just take it one step at a time. After choosing your name and registering your new blog, you will see all the choices. Start with Theme Templates and scroll through until you find one you like. If you don’t like any of them, pick the most likable one or go find another blog site.
Some blog sites, like WordPress.com have so many Themes that it can be overwhelming. That particular one is fabulous but has a much steeper learning curve. There is a book that can help you through it if you really want that one and it contains everything you need to know, but if you are mostly computer illiterate you might want to start with a more simple one.