I would suggest doing a search on Qatar Villa Rental or such and you will get a few options, I am moving back there again shortly, there is quite a lot of choice between Apartments, Compound villas and stand alone villas.
As 3 people you will want minimum 2 bed, although probably slightly bigger. From my recent searches you should get a decent villa for between 11k to 18k a month (the market has quite a few 40 to 50 K villas as well apartments start about 8K). The more xpensive ones tend to be in better compounds.
One of the things you will find is that you need to look at School location, Work location and try to get a good fit, as traffic can be a bit of a nightmare in Doha.
In terms of relying on your company to help- don't bet on it, there is a big difference in company attitudes to assisting you settle in, some good some bad.
It will take some time to get residency, Bank account etc, which you will need to rent, unless the company rent for you (not heard of too many doing that)
My personal opinion & others may well disagree, is if you are coming to the middle east for the first time, I think its better for the "worker" to spend the first month alone getting the basics set up before the rest of the family come. Unless your lucky the first month or so can be a very frustrating time.