I have a 20 ft hall with a door in the middle leading to a 12x12 bedroom, I'm planing to install 3/8 engineered hardwood glued to a concreate slab in both rooms, I do not want to use a transition at the bedroom door.

I will be runing the planks longways down the hall, the question is if I line up the floor to be straight and parallel in the hall and continue the floor through the doorway into the bedroom how do I ensure that the floor will also be straight and parallel in the bedroom?, I ask this because I want to know what to do if the rooms are not all straight and parallel, or am I being too fussy?

I'm thinking that after doing the hall I may have to make some sort of minor manual correction in the doorway area to make sure the next room is installed straight as well. Is there a professional installers trick I need to know about?

There's actually 2 more bedrooms in this project but I did not want to complicate the question, just show the principal of the question

Or should I just make sure the hall is nice and parallel and take whatever I get when I continue into the bedrooms

This is a consideration that shows a high degree of craftsmanship. That is not just "being picky".

Lay your floor in line with your main focal point. Then as you lay your flooring through each door opening, readjust you lay to square up to the room you are entering. The adjustments are usually minor. Making the adjustment on the first strip though the opening makes it easy to adjust. If you find the difference is excessive you might be able to split the difference or make other considerations.

ok, the question is how do I make adjustments?, plane down a plank or leave a small gap (I'm sure that can't be good!)

I am a real newbie, I have never installed a hardwood floor before.

As you install that first board that is both in the doorway and in the room. You will do nothing special to it. The boards that will be ripped to fit continuing the row can be nailed in place slightly off from what might be considered perfectly inline.

Actually I usually install the first row of material that is a full row before installing the ripped rows.

I find this a bit easier. So you have a fixed point of about 3' - 4'. The room is about 10' minimum. It is just as easy to place that next row perfectly inline with the rest as it is to adjust it to match the opposing wall.

I understand everything you said except the last paragraph

I'll try to paint this picture better.

The first board in both the room, and the doorway to the hall is your fixed point. It will most likely run 3' to 4' in the room. You will lay your nest row married to it along it's length. After you run past that board you will have nothing to back up your row you are laying. This makes it easy to adjust slightly in any manner necessary to accommodate any focal points necessary for the layout to look proper.

thanks Barquios,

I think I understand the principal of what you are saying, hopefully the rooms will be pretty square and I won't need much adjustment