We've tossed this around several times in here and in the "Beef" forum (if you click on the Search button at the top right of the page and enter jerkey as the keyword you will find all of our jerkey discussions) - but here are the key things to consider:
1) Temperature - You want to dehydrate the meat without cooking it. The ideal temperature for making jerkey is between 98º-120º F (36º-49º C). That is why you will see "oven" instructions saying to use the lowest setting and leave the door ajar. If using higher temperatures the meat begins to cook and then needs to be stored under refrigeration. Alton Brown's "cold dehydration" method works just fine if you want to go that route.
2) Meat Selection - regardless of the cut, you want the leanest possible. Buffalo and game meats are lean enough - for beef you want to look for a "cheaper" grade - like USDA
Select grade which has less fat and marbeling than Choice or Prime grades. Added bonus - Select grade is cheaper.
3) Slicing - the meat should be cut 1/8 to 1/4 inch thick across (aka against) the grain. If I'm using a thin piece of meat I might cut it on the bias (45º angle) to make each slice a little wider (about 40% wider). If where you buy your meat has a real butcher he can slice this for you. If not, bring your hunk-o-cow home, trim off all visable fat, slice it into strips the width you want (add about 25-50% for shrinkage), freeze until the meat is firm, then roll over on the side and cut your slices (across the grain) to the thickness you want.
4) Seasonings - there are several marinade recipes - just pick one that sounds right to you. We had a thread on this last year in this forum:
Beef jerky seasoning Since the meat is already sliced thin before going into the marinade it really doesn't take that long to marinate - usually 2-4 hours is sufficient althoug some people like to go 8-24 hours (refrigerated).
5) Dehydrating - If you are using a food dehydrator you want to use the lowest setting, if using a smoker you have to really take care to keep the temp down
below 120ºF/49ºC - this is easier on some smoker models (fire box on one and and an offset smoke box on the other) than others. If you saw Alton Brown smoke a salmon in a cardboard box ... you could use that method, too. If you are going to use a smoker method you want to use a marinade that does not contain "liquid smoke".
I use the oven. Place both oven racks in the center of the oven and turn it on to preheat while you prepare your meat. Remove the meat from the marinade and blot dry with paper towels. Then lay the strips on the oven racks to that they are not touching or overlaping. If I am making more than will fit on the racks this way - I use wooden skewers to skewer one end of the meat and hang it from the oven racks - leaving 1/4 -1/2 inch between each strip for air circulation. If you are going to use the oven, one thing that you really want to do is line the bottom of the oven with aluminum foil to catch any drips. At the proper temp there is no need to oil the racks, and the skewers will not catch fire. Well, I never had a problem with either of those things.
It will take 6-8 hours to be done. You can tell when it is done when you can bend a piece and it just cracks. If you can bend a piece in half and it doesn't crack - it's still too wet. If you bend a piece and it breaks - it's really dried ... officially one step over the line - but still good.
6) Storage - When your jerky is done, let it cool completely. If you have kept the temp below 120ºF - you can store in zip-lock bags (or some other air-tight container) on the counter for a week or two- although keeping it in the refrigerator will prolong it's shelf life. If properly made and you vacuum package it - the unrefrigerated shelf life goes up to 6 months to a year. If you have followed one of the other sites that suggest 140ºF - it must be kept under refrigeration since it is on the edge of the cooking temperature.
Making jerkey is not that hard to do - it's just a matter of working up the courage to try something new.