Paper/poly drop cloths: $2 to $6 for 9x12-feet. The best of both paper and plastic, these cloths are low-cost and disposable. They absorb paint drips while providing more protection for what's underneath. They also provide some protection from slipping. Plus, you can cut paper/poly drop cloths to fit the space. But, like paper, paper/poly drop cloths can rip more easily than plastic or canvas drop cloths.
Plan the budget. Costs will vary greatly, depending on price and quality. Choosing mid to upper-grade paint, expect to pay in the area of $350.00 in paint alone for a 2000 sq. ft. house. Add another $100 to $200 in brushes, rollers, pans, tape, and other materials. Don't forget food, if you plan to feed your workforce. When it comes to materials, not all paints are equal. Some truly cover with one coat, some say they do but don't. Your costs will double if you have to apply two coats to everything, so buying the cheaper paint might cost more in the long run. Trust your paint professional salesman (to a certain degree) to tell you which paint to buy. You can generally go cheap on primer, expensive on top coats.
Repainting is key to maintaining exterior house paint. The material that your home is made of affects how often you should repaint. For instance, wood-paneled homes need to be repainted twice as often as those made of stucco. Environmental factors also play a role in how often you should repaint, since harsh climates can be hard on a home. As a general rule of thumb, homeowners should repaint their home every six to ten years.
Exterior paint averages $25-$40 a gallon, and a 3,000-square-foot home takes 15 or more gallons of paint, or $375-$600 just for the paint. However, really premium paint can cost $50-$100 a gallon, or $750-$1,500 for that large home. Doing it yourself also requires renting a pressure washer or sprayer for $50-$100 a day; extra-long ladders or scaffolding at $20-$75 daily; and a power sprayer for $50-$100 daily, plus masking tape, drop cloths and other supplies. However, it's possible to paint a large, two-story house for materials-only costs of $400-$600.
Before hiring a painter, you should get a detailed estimate from them. This should include costs for labor, materials, paint, and the timeframe of the project. Covering details upfront will prevent issues from emerging later on. Ask the painter if they charge for travel time, whether their estimate includes pressure washing and caulking, and any other questions you might have.
If you have kids, pets, or occupants who will damage the walls, it is recommended to go with washable matte, eggshell, or satin, because these paints can be easily cleaned and are more durable. However, flat paint can be touched up more easily and hides imperfections better, so if you are selling the home, it is highly recommended to go with flat. Bathrooms with showers/tubs should go in semigloss- unless you are selling or want a specific design look, then use satin. 
Begin prepping your walls by removing any outlet covers or lighting fixtures (if possible). Next, inspect your walls for any defects. If you encounter cracks, dents, or holes in your walls, simply fill them in with caulk or spackling compound. There are also a number of DIY tips to fill nail holes. Once your repairs dry, smooth them down with sandpaper and wipe the walls down with a damp sponge.
Prepping a house costs anywhere from $0.50 to $2.50 per square foot. This is almost always included in the total project price. However, the DIYer might negotiate some discounts for completing this work on their own. Be warned, proper prep is key to the quality and durability of the finish. If you do this work yourself, the contractor might no guarantee to finished product.