Ok, for dating go to:
http://www.singerco.com/support/serial_numbers.html
Or send me the number. I have a lot of them printed off and it's sometimes quicker to just let me look it up in my binder.

For manuals for many machines, contact Cindy Peters at:
stitchesintime@earthlink.net
She sells really nice reproductions of original manuals.

The best way for me to help you learn more is to see some pictures of your machines. That way I can ID the models and tell you more about the machines.

Most sites are research sites and frankly are difficult to navigate unless you already know what you are looking for.

Annie

Annie I need your help again too please. I don't remember the model of my MIL machine SR # EF 781701.

I took a look at it over Christmas. I put a needle in sidways like my Featherweight. I got it sewing but the stitch is not good. This machine does not have a bobbin case so I have no idea how to balance the upper and lower tensions. It growls when you sew too...doesn't run smoothly like my featherweight and I recollect the Singer service man stopping there every time he was in town. I think there was a lot of playing around with this machine by a few different people. I think I would need to get a fix it manual to do much with it. I always appreciate the help you provide. Thanks
Jean

Ok, it looks like you've got a 201K (The K simply tells us that it was made in the Kilbowie, Scotland plant.)

Cindy will have a manual for this as well.

Make sure your needle is oriented with the flat side to the right. Describe your stitch to me--top thread pulling through to the back? Bottom thread pulling through to the top? Both too tight or loose? I usually fiddle with the top tension first, only working with the bobbin tension if that doesn't work.

Annie

I have a National Stretch Series 3000, no manual and haven't located one online. I can get it to straight stitch but the decorative and zigzag stitches aren't working. Is there a button, lever, etc. I'm supposed to engage in order for these to work?

Not a problem. got it figured out