I am doing the majority of my house next month, 1,300 sqr ft of the total 1800 sqr ft. This will be a total of 3 bedrooms, 1 hallway, a dining room and a living room.

My question is regarding transitioning. Im find with how to transition to my tile flooring my the bathrooms, kitchen and foyer, but what is the proper transition from room to room when using the same wood throughout? Do I lay a board perpendicular to the direction of that room at the doorway to create a "stopping point", do I continue through the doors into the other room creating one seamless design, do I switch direction in the rooms so they are different from the hallway direction?

Whenever I search for transition information online it is always from wood->carpet/tile/other wood. I never can find information about transitioning to the same wood/different room.

I have done flooring before but only in one room at a time ever, never a multi-room project.

Thank you!

If you want the rooms to flow together then continue the flooring without a floor joint. A floor joint can just be two boards that have a slight bevel at the edges.
Usually the floor joint is under a doorway so if there are two different materials the transition will be under the door so you will see the materials change under the door, but match the room with the door closed, from either side of the door that you are looking from.
One reason for a floor joint would be so you can re-finish one room without disturbing the adjacent room, which seems practical, however wear patterns through doorways make re-finishing one room hi light the wear in the other room.
A transition with a header board laid perpendicular to the flooring will make a kind of boundary as between the public and private places in a home.
I like to have a header board between different materials, especially between tile and wood to add a little extra strength so the wood will not deflect and cause cracking more easily at the edge of the tile. This header board can help get the elevation difference to be less of a tripping hazard.
With a good sub-floor you can change direction wherever you like.