If you have decided to branch out form knitting or crochet and try your hand at sewing, be advised the variety of machines is bewildering! Resist getting distracted by all the special features on the high end machines. Even professionals use a simple straight stitch most of the time!
While I have been a lifelong Kenmore seamstress (Mom worked at Sears over 40 year) I found a good review of this Brother CS6 machine. It looks like it has just the features a beginner wants, such as an automatic needle threader, without many expensive distractions.
A word of advice if you are teaching a child to sew: Don't bother with a toy sewing machine. A good basic machine such as the Brother I mentioned before is not expensive and will enable the beginner to have a real sewing experience. Toy sewing machines and knitting machines often break after relatively light use. By choosing a grown-up model, you can use easy-to-find needles and accessories instead of special toy parts, too. Treating the learn-to-sew project seriously also shows confidence and promotes successful sewing, which leads to more successful sewing....
Check out the What Rocks site for more reviews, too.