Now that you have your account, just log in as shown on the picture. Click on it for a larger size.
To create posts, the most important part of the following menu is Posts.
In Posts, you have an overview of all the articles already posted and you can edit them by clicking on their name or you can create new one by clicking on “Add New” near the top of the window.
The second important part to create redlab posts is the Media menu.