Plastering is one of those skills that you can't really muddle through without some training and knowledge. As Arch says, I had the help and guidance of a friend who has been plastering his own house having done a course and has a friend who is a part time professional plasterer.
A ceiling is a really tough place to start for a novice. Aside from the lack of ability, you will get about 1/4 done and your shoulders will be screaming out for a week's rest. However, you can't stop and will have to finish a whole surface edge to edge.
Having a second person to mix, and a third person to get water and plaster ready to use and clean everything will help. Make sure everything is spotlessly clean, water tools, buckets, surfaces, everything. Set up a good working platform so that you can walk around and work without having to balance and watch your footing as you go. I have a small scaffold tower on wheels but a scaffold plank across two ladders would do.
Start at the corners and work in towards the middle. Start off by just getting the surface 'buttered' over as evenly as you can without worrying about how smooth it looks. When the surface is covered, have a

and then use a plant sprayer to wet the surface and float off to get it smooth. Use a really good float, a cheap one won't work and will mess up the plaster.
I have only just done my first bit of solo plastering on a shower ceiling. The ceiling has a curve in it as it goes from flat to following the slope of the roof line in to the eves. The area was only 750mm x 1300m that I covered and I was starting to ache even then. I then did a velux window reveal and then went back to the ceiling to float it off.
It isn't wonderful but small enough to sand smooth now it is dry.