Difficult, this heading. For the family it will mean help with coming to terms with your incarceration, monies and the loss of a part of their lives.
For you it means the inability to be able to help with anything physical or immediate. Nothing comes close to the helplessness you feel when a problem hits the family you can do nothing about.

So from the very start you all have to understand the basics of communication. Your talk time should be devoted to practical things, try to keep your emotional stuff in the background, on visits and the telephone. In your letters you should all throw in your emotional stuff and then some. Keep reminding the family of the good things done together, the things to come and the problems you feel can be sorted by the use of x,y,z or whatever.

The family needs to expand to include members who you would only see at Christmas and funerals, thereby helping your immediate family to cope a little better. If the family has lost you as a breadwinner, they need to get into the DHSS office as soon as possible. The state does not care about prisoner's family and would rather they were not there. In some cases, the system could actually be accused of attempting to split families for their own ends.

Do not expect help from anyone, the only reason the Social Services get involved is because they may drag up something to keep them employed. So much power in unbalanced hands is quite frightening to see!
Keep it in mind if they come calling, like Religious born again saviours, they are pious enough to think their gospel and bible is the only truth in the world. I pity whatever family they touch.

Try to think positively and project this towards each other, in times of stress. Never forget if you have children, they will be bewildered by this split in authority figurers around them; before all the mess they would have believed that police and the courts were as friendly as mum and dad, their reassessment could change their lives, forever!