The first thing you should do is gather all of the supplies that you need. Do not skimp. Instead buy all of the necessary supplies and a few extras. You can always return unopened merchandise. You will need paint brushes in various sizes, rollers, tarps, painters tape and a variety of other items. Ask for help at the paint department for advice on what else to buy.
After you have bought the supplies you will need to buy the paint. Before you go to the store you need to calculate your wall space. Take the width times the height and add up all of the walls. Do not forget the ceilings if you are painting them. Take the total and look at the spread rate on the paint to determine how much you need. Buy a little extra to account for waste and so that you have paint to do touchups with.
Lastly before you actually start painting you need to do extensive prep work. Move furniture out of the way if possible and put tarps over non movable furniture and floors. Use painters tape to mask off areas not being painted. Also take the time to fill in any cracks and holes in the wall. Take your time with the prep work and the painting job will go smoothly.
I hope this article has been of help to you with your home painting project. If this seems like too much work or too much of a mess you should consider hiring a professional painter to do the work for you. It is surprisingly affordable and much much easier. Good luck to you.