Neither set of instructions is really right. Bottling at one week will probably be fine but the beer may not be done fermenting yet and bottling beer that isn't done fermenting gets you gushers or possibly bottles that explode. At best it will get you bottles with a lot of sediment in the bottom that you will want to leave when you pour. More time in the fermenter lets this settle out there instead of in your bottles.
Leaving the beer in the fermenter for 2 to 3 weeks works out better but after bottling a minimum of 3 weeks before opening will get you better beer. For your first beer however, open one bottle at a week. Open a second bottle at 2 weeks and see if you notice a difference. For most beers this will be noticeable. For your Octoberfest, it should be pretty much done with the changing by the third week. Darker beers and beers with higher alcohol will take longer.