The Basics You Should Know Before You Start.
If you have worked with other people on projects like this before, you may know most or all of the things I will cover in this article, but if you are setting out on your own for the first time, these are the key points which I found incredibly helpful to know.

Depending on the experience of the director, producer, picture editor, and most definitely the “on location” sound person, your job can vary a bit in its scope. Just know this, mixing music for bands is going to seem a lot easier after you get done mixing sound for film.

Calibrate Your Control Room
Project Timeline (Scoping)
Normalize your dialog
What Format?
Stereo or 5.1 Surround?
Sample Rate and Bit Depth
Get a Good Loudness Meter
Broadcast Standards