One of the most important things that is often overlooked when moving to Israel is budgeting. The costs in Israel are generally not the same thing as they do in the US. For example, when we moved here almost 3 years ago, I thought we had enough to live on for 6 months. We ended up with enough for 9 months (Thank God). Having an accurate financial picture is very important but also not easy to come by.
I would recommend discussing various costs with people you know in Israel who are in a similar family situation as you are. Sit down and write out the standard expenses that you are expecting every month. Remember, all the numbers that you have been working with and understand up until now are practically worthless. For example, we spend approximately 20% less here on food every month. Gasoline in Israel costs about $5/gallon.
What I recommend is starting with an estimate that includes: rent, car and gas (if you're going to buy one), electricity, water/sewage, arnona (municipal taxes), food, phone, internet, entertainment, house/garden (if you need to buy things for this), schooling (if you are planning on sending to pre-gan or private school - regular schooling doesn't cost that much), clothing (including shoes), chugim (extra curricular activities) and any other category you can think of.
Ask 5 people from the community you are moving to what the rent prices how much they generally spend on those categories. Remember, winter and summer are different for things like water and electricity.
You need to talk to people in the community because a lot of the numbers depend on your community. For example, if all of your friends send their kids to chugim, you will probably also. If none of your friends send their kids to chugim, the odds are that your kids won't want to go.
We've found budgeting to be very important, especially when you are starting again from scratch and don't have the experience of approximately how much you spend every month.
Just thought I would share.