I just drop the feed dogs on my 201 and rarely think to check the stitch length. Some people prefer to FMQ with the feed dogs up, in which case, you should try for "0" like deemail says.
One thing that helped me a lot with trying to learn FMQ on my jackrabbit machines (15-91's) is a router controller. You can buy them at Harbor Freight for about $22 - they are a type of rheostat. (You should NOT use a rheostat on any electronic or computerized machine - only on the mechanical electric ones)
You plug the router controller into the wall and the sewing machine into the router controller. Set it on Variable, then dial the power down so that the top speed feels easy and comfortable to you. You will be speeding up gradually as you become accustomed to moving your quilt under the needle. Eventually, you will be able to give it up and start practicing on controlling the speed of the machine and the speed of your hands at the same time, but to only have to concentrate on the speed of your hands for a while is wonderful practice. You just step on the gas and hold the pedal at full throttle.
If you have one of those button-type bakelite foot controls, this will keep your control cool, too. Slow stitching for several minutes at a time (or more) is what causes the foot control to get so hot. Either run these button controls full open or sew for short periods and allow breaks in the sewing so that the heat can dissipate.
Hope that's helpful!