Before you upload any images to your website it's important that they have been sized correctly and optimised.
See the following tutorials for sizing and optimising images:
Once an image has been uploaded you should attach apply metadata information to the image so search engines understand what the image is about.
Select an image in your image library and edit the following fields in the right hand column.
Note: Everytime you make a change they are automatically saved.
If you want to add more media categories see tutorial Adding Media Categories.
It is possible for you to create more media folders should you need to. You can also create nested folders which can be quite useful if you have a blog post with its own large gallery images.
To create a new image folder to the following.
The new folder will be created. You can easily move the folder into another by dragging it.
To delete a folder you must Control click and select Delete.
Before deleting a folder move the images to another folder first.