I don't make beef jerky but I make deer jerky. though I'm sure its the same process.
We use a deli style meat slicer such as this one,
http://www.google.com/products/catal...ed=0CH0Q8wIwAA
we Slice it about 1/8 inch thick, no thicker.
Time for marinade! it doesn't matter what marinade you use, we use something like this one:
http://www.cooks.com/rec/view/0,1627...254193,00.html
Though we don't use those exact ingredients. you can create your own, or go off of one you already like and adjust the ingredients to your taste.
We let it marinade overnight in the fridge, sometimes two days.
After it has been in the fridge over night put it on a dehydrator, we use one like this:
http://www.target.com/p/Ronco-5-Tray...gpa=pla&ci_kw=
we shift the trays every few hours so that the deer meat dehydrates evenly. Usually about eight to twelve hours depending on your thickness