This Instructable explains how to use a particular sewing machine, the Necchi belonging to the Noisebridge
hacker space in San Francisco. It will be helpful in understanding sewing machines in general if you aren't familiar with them, but yours will differ in details.
A sewing machine stitch is different from a hand sewn stitch. The machine stitch consists of two threads, one on each side of the material to be sewn, which loop around each other to make one stitch. Thus a sewing machine has two threads, the main one visible on top of the machine, and a smaller bobbin of thread that's hidden away inside.
This instructable will show you how to remove and insert the bobbin, how to thread the machine, how to wind more thread onto a bobbin. Coming later, once I've taken more pictures: how to operate the machine.
Note: the foot pedal/power cord assembly is detachable, but can only plug in in one way. Also, there is an on/off switch on the right side of the machine. When it's on, a light will go on by the needle.