When you answer your invite, you come to what is called "The Dashboard. If you want to add a writing, click on "New Post", which brings you to a box to write your article which has some formatting buttons on the top. Above that box is the title box, which I already wrote about. (See previous post.)
Some things you can do here -- check your spelling, add an image (photograph or other) and if you click the preview link you can see how it looks. When you're done previewing, just click "Hide Preview" and you're back where you started from.
If you give it a title the article stands out more, but it's not necessary. Same with the box (at the bottom to the right) for labels. You can make a label or pick one already made, to see what is available click on the link "Show All."
When you're done with your article click on the "Save Now" button (at the bottom left) and then click on the "Publish Post" button next to it. You will then have the option to "View Blog," by clicking on that link. Isn't it nice to be published?