With the post editor open, click the Options button in the toolbar to reveal the options side panel. Available options vary depending on the features your blog system supports.
To set categories for your post, check the categories int the list. For blogs that support adding new categories from MarsEdit, you can add new categories, which will be created when you send the post to the blog.
If your blog doesn't support adding categories from MarsEdit, you will need to add the categories first through your blog administration page on the web. After you've added the new categories, click the Refresh toolbar button from the main window to update the list of categories in MarsEdit.
In general, a post sent from MarsEdit to your blog will be published immediately, unless the blog is configured to handle it differently. Some systems provide a means of specifying that the post should be saved as a draft on the server. When available, that option will be listed here.
Important: support for this feature is spotty on some systems, such as Movable Type. Until you are confident with the functionality on your system, you should take care not to send private information to the server with Draft status. You should also confirm that the item was published as a draft, by visiting your blog to make sure it is not publicly visible.
Movable Type and TypePad support a powerful feature that allows you to specify which format the server should interpret your content as. For instance, if you've written your post in the Markdown formatting language, you can use this popup to select the appropriate Markdown filter, so that your blog server will know how to interpret the post.
Most other systems do not yet support this feature.
Some systems let you to choose whether to allow or prohibit comments and trackbacks/pingbacks for your blog postings, on a case-by-case basis. When available, you can use this option to set permissions for your post before you sent it to the blog.