eligibility?

I am an American born Belgian dual national who is soon to be going to England to see my husband with our 2 year old daughter. He has been telling me he thinks we may be eligible for child benefit. The situation is that we were living in the US and he was deported and then imprisoned for a previous conviction when he arrived back in the UK. He cannot provide for us and I'm not sure I will be able to get a job (or at least one good enough to support my daughter and I) for a while. He still has 6 months left in prison and then is out on tag for 2 years. Are we eligible for any benefits? If so how do we apply for them?