Ever had a file you just didn’t know what to do with? or ever wondered where those images you add to post or page content go? There’s a good chance they’re in your wordpress site’s media library.
To get to the media library, log in to your wordpress admin menu (yoursite.com/wp-admin/ usually), then click “media” in the left column. This will pull up your media library, showing all the images/PDFs/etc you’ve uploaded through wordpress.

Tip #1: To edit an image using wordpress’s image editor
1.Roll your mouse over the row the image is in, and click “edit”.
2.In the next menu, Click “edit image” under the thumbnail.
3.The awesome wordpress image editor will pop up, showing your image in the center area.
4.You can edit the basics of the image with the top row of buttons. The first button will allow you to crop the image, by dragging and editing a square box that pops up. The second button allows you to rotate the image counter-clockwise. The third button allows you to rotate the image counter-clockwise. The Fourth button lets you flip the image vertically, while the fifth allows you to flip the image horizontally, like a mirror. The sixth and seventh buttons allow you to undo and redo things  you’ve done while editing the image.

Tip #2: How to find the location of a file
1.Roll your mouse over the row the image is in, and click “edit”.
2.In the next menu, Click “edit image” under the thumbnail.
3.In the menu that pops up, you’ll see a row called “File URL”. The darker gray box at the right is your File’s location and URL, voila!

Tip #3: Attaching images to posts as their featured image
For each image’s row, you’ll see a column called “Attached to”. This column tells you how the file is used within wordpress.  This attachment can be anything from the featured image of a post to a just an image embedded in one. It can also be any other attached file type as allowed by wordpress.
To attach an image to a post, find the target image’s row and click “attach” underneath the “attached to” column. This will open up a new dialog called “find posts or pages”. Enter the name of the post or page, select “posts” or “pages”,  then click “search”. Next, select the radio button next to the page or post’s title, and click the big blue “select” button.