Find an image you like and send it to the printer; make sure the paper you use is printable Vinyl. 

Save the photo you like to your files and open design space on your computer. 

When you open a new project for design space use the upload button on the left side of your screen. You can make it transparent or keep the background. When your done editing the dimensions press make it on the top right hand side.

When your image is done printing put it face side up on the Cricut mat and press it down a bit. 

You'll want to let it be between the rollers and its arrows will light up. Press it so the mat rolls inside.

Press the blinking cricket button and wait for it to finishing and take it out.