Feel free to use this thread to post your questions, and I'll do my best to answer them promptly!

When you are ready to publish an entry, you have to be sure to check the "Published" button under "Post Status"in the righthand column in addition to clicking the "Publish" button under the text window.

It's there now - it had been set to not be public somehow, but I changed that.

To add categories, go to Manage and then Categories in the menu bar.  From there, click on the link that says "add new" next to Categories.

Alternatively, as you are writing an entry you can add a category right there.  In the righthand column the there is a field to type in a new category and then click "Add".

Hope that helps