It's up to you. Outside is much harder because it requires more prep, patience, time, help, money and of course, effort. I have been painting my own houses and rental properties interiors for 20 years, and I painted the exterior of one, once. I then had it promptly done again by professionals who said it would have been cheaper if they didn't have to undo my work first. My advice is to get pros for the outside because everyone will see it.
The Ceiling. For ceilings, flat is recommended, except semigloss or satin should be used in bathrooms with showers/tubs. Some customers opt to go with a different finish for ceilings in general, to create a specific design look, i.e. high gloss ceilings on dining room tray ceiling to make a statement, or eggshell ceilings throughout to look modern and make a statement.
If the exterior of your home is unpainted or has been scraped and sanded, you will want to lay down a coat of primer. Make sure that the primer you’re using is right for the surface you’re painting. While most surfaces can be treated with acrylic primer, some surfaces, like cedar and redwood, require oil-based primers. The oil stops the wood tannins from bleeding through the topcoat.
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.
Most of a projects price is the cost of labor at $25 to $75 per hour. However, most contractors bid out based on the entire project which includes all work hours. Hourly rates are only useful if your pro asks to do the job as “time and materials.” However, be wary of this pricing structure, it usually shows the contractor is uncertain how long the project will take.