Children are messy as it is. When one or more of your children is extremely creative and artistic, you can bet that his/her creativity is visible on all the walls, furniture, doors, doorways and cupboards in the house. When they have finally reached an age where they no longer put their personal touches on every surface, you can finally repaint and clean up the whole house. Here is how to prepare for this project and hire the right people.
All of the walls, doors, and doorways in your home have to be scrubbed clean. This is quite a chore given what your children have done. Hire a cleaning service and explain to them what you need completed and why. Then the cleaners can put all of their elbow grease into wiping marker, pencil, pen, and crayon from your home. There may be some places that will not come entirely clean (e.g., permanent marker), but those areas will not be affected by the painter's work.
Residential Painting Service
For a project this big, you should hire help. A residential painting service can divide the work up so that a six-member painting crew can paint at least three areas at a time. If you are also painting a room, that should help get the job done much faster. Be sure to request paint that combines primer and paint in one, so that it completely covers any and all remnants of the "art" your kids left all over the surfaces of your home. If there are some really dark spots where an entire drawing was colored in with permanent marker, apply a couple of coats of straight-up primer first, and then the primer-and-paint over the top of that.
Window and Door Contractors
If you want to paint your doors, you can. Given what it costs to just replace an interior door, it may be more beneficial to just remove these doors and replace them with new ones. That is especially true if you would rather preserve the wood look of the doors and not stare at child art or painted wood indefinitely.
Obviously, the painting team cannot paint your wood and tile floors, and painting carpet is not a good idea either. A flooring contractor may be able to buff and sand out the "artwork," thereby saving your hardwood floors. Carpet, unfortunately, will typically have to be ripped out and replaced.