There isn't one right way for everyone.  As you're getting started, try to be aware of your personal ergonomics and what feels comfortable and natural.  As much as possible, leave the spaces adjustable for the first few months so that you can rearrange until everything is right.

e.g. I work from left to right.  I can't work angled over a sink for long periods of time, so I elevate what I can and have a relatively narrow sink.  I've set the ventilation hoods below my head level, with storage over the hoods. I've set the sink height just right.  I have florescent stick'ems at strategic spots. The ventilation is excellent.

The darkroom is one place where it's justified to indulge yourself.  A place that is comfortable, workable, and welcoming is a place you'll enjoy spending hours.