To start the building you need to have 15M lumber, 15M stone and 7.0 or 7.5M silver and 100 "Scrolls". It is not possible to use Gold for upgrade. Building time for level 1 is 1w 3d 0h (fairly sure. I did not remeber to make some wiki entrys before it was started already). Only the cheif or any of the Elders can start a construction process, but all clan members can send rss to the Stronghold Resource Storage.
For speeding up the building process or the brewing you use a Stronghold Boost.
The brewery converts Food to Ale and the brewery time is shortened if you use more food. Base time (longest) are 10k food for 1 Ale. 1M food/1k Ale at slowest speed are almost 1 month.
For level 1 the stats are
Maximum of Ale recieved: 2000
Stronghold Influence: +62M
(someone else can make a proper table later)