The first step to threading a sewing machine is winding a bobbin. Do this with the same thread you plan on using for the top threading of the machine, this way they match each other. 

• First step in threading your machine
• You want to wind a bobbin with matching thread to what you will use in the top of your machine
• Take the end of your thread off the spool & thread it through one of the holes in the top of your bobbin, so it is coming out the top of the bobbin
• Be sure to pull the thread to have enough slack to hang on to
• Place the bobbin on the bobbin winder, with the tail coming out of the top
• Push the bobbin winder into place
• If your machine does not automatically deactivate the needle for bobbin winding, do so now
• Give the thread going from the bobbin to the spool tension
• Be sure to thread the tension the way your machine indicates & that it is securely in place
• Hold the tail coming off of the bobbin firmly in your hand
• Start winding, slowly
• Stop when the body of the bobbin is covered twice
• Trim the tail off the top
• Continue winding until the machine skitters & slows
• Stop winding & trim the bobbin off
• Release the bobbin winder & reactivate the needle if need be