For older machines, you use a darning foot. Some of the newer ones actually have something called a Free Motion Quilting foot.
I like the open-toe darning foot. It's easier to see. I also make sure to mark my quilt lines before starting because otherwise I get confused. Plenty of quilters just figure it out as they go along or can sketch their design on paper and remember it. I can't. I learned from Leah Day's free classes. She is a very talented teacher & also offers classes on Crafty for a fee, but why pay when you can get it for free?
https://www.youtube.com/watch?v=6nz0QwNv1AA
Note: I did not modify my foot or order from Leah Day. I went to my local sewing machine repair shop & bought the appropriate darning foot for my machine with an open toe.
Here is her 2012 series, which is what I learned from:
https://www.youtube.com/watch?v=fFcI...1F4B76430BB141
In 2013 she puts several of those quilting techniques together in an original quilt she designed called Express Your Love. That series is also excellent:
https://www.youtube.com/watch?v=A4UAmannTUo&list=PLNkZhEjxH0nJBtcOZMLgEcJrcUzxr1Opt
In 2014, she paired up with her husband Josh -- a true beginning quilter -- to create a new series on her blog called Building Blocks Quilt Along. Honestly, I found that series to be much more confusing. It combines together piecing and quilting techniques in quilt-as-you-go sampler quilt. I had originally planned to do the quilting with Leah & Josh each week, but was not very excited once I saw the number of weeks that had me quilting in straight lines. There's nothing wrong with straight line quilting & you can do it with a darning foot but I'm not trying to win awards for my quilting yet and would rather just swap in a walking foot than spend hours learning to reproduce the same effect without feed dogs. If you're interested, here's the link to her blog:
http://freemotionquilting.blogspot.com/p/blog-page.html
The Dancing Butterfly Quilt Along for 2015 looks much more promising.
Good luck! Free Motion Quilting is really fun & doesn't take that long to start to get good enough that you can begin to incorporate it in your quilts. I think I'd heard it takes 2 hours or so to get enough practice to start stippling & that's probably about how long I practiced. I ended up ripping out a few places on my first quilt after the practice changing pads, but mostly I was really happy with it.
I also learned a lot from Heather Thomas. Here's a link to her beginner video series:
https://www.youtube.com/watch?v=LLWFmOForjU