When placing a row of boards along a wall that has doors leading into other rooms should you,

1. Split & cut the row of boards so they slide up in the doorway?
or
2. Place the boards along the wall & insert a smaller piece inside the doorway?

When running flooring through a doorway, the material should continue as the door is not there, therefore you may have to notch the pieces that go through to the next room.

EXAMPLE: If you are using flooring that is 4" wide and the last full row in the room is only 2" wide, you make a piece that starts at 2" runs up to the door opening, 90* cut to 4" for the width of the door, then back to 2" (you have to repeat this process on the other side, in the next room to keep the flow of the rows correct.)

If the flooring ends at the door, make your notch so as to allow the flooring plus the transition piece to end directly under the door (or in the center of passage if no door).

Hope this helps, please feel free to contact me for further info

CLARIFICATION: For Pleasant et. al.
IF you are starting on a wall with doors, it is fine to lay a full width row first then fill in the doorways with pieces that fill that space. However being a carperter professionally I prefer having the first and last rows to be equal, so the notching thing still applies. For the DIY'er full first row is fine (98.7% of the population of the US and 100% of the population of China won't notice). Hope this make things a little clearer.