Dammam is one of the oldest cities in saudi arabia, hence it isn't well planned and I would go as far as calling most of dammam the Ghetto of Saudi Arabia.
You will find most of the natives living over there. Is that a good thing? Definitely not if you are a foreigner, but the good news is that dammam is just about 30 mins away from a city called Al-Khobar.
Khobar in direct contrast to dammam, is a well planned city and most of the foreigners live over there. There are some really good apartments you can rent for about 16,000 riyals per year. The rent really depends on the locality of the house, some places rent out for as cheap as 8000 per year.
There are a lot of international schools here, but most of them aren't up to the mark. There are 3 or 4 American/British academies and they cost about 18,000 riyals a year. The other private international schools are much cheaper.
A domestic helper can be found pretty easily, they have variable rates but most of them ask for about 150 riyals a month to clean up the house every day.
My advice, stay clear of dammam. I am not saying all Saudis are bad people but some of them are, and trust me when I say you want to keep yourself and your family as far away from them as possible.
It won't be much of a hassle if you get a house in Al-Khobar, its a really nice place to live in and is just 30 mins away from dammam.
Hope this helped...