First, click the “Add Media” button above the Visual Editor:
Then upload your images:
Or, to create a gallery, click on “Create Gallery” on the left side of the window, and then select the images you wish to include:
Then, click on the Create a new gallery button in the bottom, right hand corner of the Media Manager:
If you love video, you can also embed videos on your blog from supported services, such as YouTube and Vimeo. Copy and paste the URL from your address bar — on its own line — into your post, publish the post, and you’re done!
Or, with the VideoPress upgrade, you can upload your own videos directly to your blog with the Add Media button — just like adding photos.