Wheel Building - Should key spoke be inside or outside flange? I’m working on my first wheel build and reading a lot of articles about spoke patterns. Some articles say the key spoke (drive-side, to the right of the valve) should be on the outside of the flange, but others say inside of the flange. 

Is there a recommended/better flange side for the key spoke? And then what is the recommended flange side for the spoke on the other side of the valve?

In my current build my key spoke is on the outside of the flange. The parallel spoke on the other side of the valve is inside the left flange.

Update

Here’s my finished wheels showing the lacing pattern. I followed Shimano’s recommended pattern but would love to know if it looks in/correct to anyone. In both pics, the wheels are drive-side up, with the valve at the top-center (in the T of WTB). All spokes on drive-side go to holes on drive-side of rim, same for non-drive side.
For the pulling spokes, the knee should be at the outside of the hub flange (i.e. spoke heads inward). 

If you look at the wear marks of a used hub (picture below ; pulling direction clockwise) you see that the pulling spokes leave a strong impression on the hub flange. Such marks are absent on the inside.
The knee of a spoke is the most vulnerable spot. With the pulling spokes running tangential on the outside of the hub the load on the knee is shifted to the line of contact of the spoke with the hub. Also the dish (see https://en.wikipedia.org/wiki/Bicycle_wheel#Dish) is larger when the pulling spokes run outside, which increases lateral stability.

In building a wheel and making final adjustments in spoke tension, you often have to add or reduce a small amout of tension on each spoke. It is difficult to avoid a torsional wind-up because the nipple doesn't rotate freely. There are many craft practises to reduce and release this wind-up, but often they leave some residual tension. If the pulling spokes are running inside the hub, the wind-up tension is mostly concentrated on the knee of the spoke. If the pulling spoke is outside the hub, the wind-up tension is more distributed between the nipple and the hub.

For disc-brake wheels, the spokes on the disc side running forward share most of the braking force. So they also should be mounted with the spoke heads inward.