Hi. I had the most astronomical success with my first five turkeys. Here's what I did and for how long.
Got turkeys at one week old and kept them in the house for approximately one week. Put them outside in a little house and gave them a raised run of about 8'x4' (this with the house included was probably 11'x4'). I fed them several times a day on normal turkey grower and all the extras from the garden, fridge, etc. Nothing spectacular, nothing extreme. They really thrived on my actually being there and talking etc. (not for everyone tho). When I had them processed at 4 months of age, the older gentleman that did it could not believe how young they were. They were just your "run-of-the-mill" white turkeys from the Cooperative in Nova Scotia. They dressed out at 35 to 40 pounds each (all Toms) and this was supposedly big for age and all that happy stuff (first and only time I did it). I've read that keeping these guys from roaming around really puts the weight on them and, where we were raising them for the table and in a short growing season, it was the best way...it worked...but to keep your conscience clear go down and baby them a bit. I certainly wouldn't want to hang out in a small but outside room for four months.
good luck