Im doing some work for a couple people right now and Ive found that they all want theyre stuff formatted differently. So just ask them how that want theyre stuff arranged. Some people are super specific about how they want it, others arent.
For payment probably best to discuss with the other person and come to an argreement on whether youre payed per asset, all at once, per hour or whatever. But try to figure out what kind of rate you would be willing to accept first.
I like to send a sample image first, which is the finished imaged but with blur and noise added. Then once they send the payment I send them the actual file.
When I do commissioned work I started logging in th exact time I spend on all the work. Because people always like to ask how long you think certain work is going to take, and I had no idea how long I spend on stuff until I actually started keeping track of it. This helped me figure out what kind of rates to take too.
Sorry I dont know about any of that other stuff though, I just started doing payed work recently myself.
