Only Platinum Partners can submit blog posts.
Once you are logged in you will see a tab labeled “BlogSubmit” on the top of your profile section. When you click on this tab you will have access to a form submission page. During that form submission you will be asked for the title of your post, what categories it should be linked with, a section to paste your post content/text that you have already written and a upload button for your associated image for the blog post.