How difficult is it to paint the interior of a house?

[UncleWai]

Well, actually it's only the bedrooms.
The previous owner let his kids crayonized the walls.

Can I just buy a bucket of whitewash and a paint and start painting?

 

[Yossarian]

you can only use whitewash if you're Tom Sawyer and you're working on a fence. sand sand sand then put down a couple coats.

 

[Banana]

Don't forget to remove the crayon marks first--paint doesn't adhere well to that waxy stuff. It's easier to repaint a wall with a similar color.

 

[HappyPuppy]

With your conditions I would set aside an entire weekend for each room to do it right.

 

[bunker]

You're either going to have to put a coat of primer over the crayon marks or sand them off.

The paint won't stick well to it.

 

[Wingznut]

In the past year, we've repainted the living room, kitchen, dining room, family room, and laundry/bath rooms. We didn't sand anything but the wood (cabinets, moldings, etc...)

Just mask off the things you don't want to paint, buy paint and equipment (rollers, brushes, etc) and get to work!