family visa residence stamp will expire soon

Hello everyone,

I would like some guidance regarding the next steps we need to take to extend my husband's right to live and work in the UK.
He was granted a family visa residence stamp valid for 5 years and that will expire in march 2015. I am an EEU national, my husband is indian, we married in the uk and have a 4 years old son.

During this 5 years i was exercising my threaty rights as self employed and since 3 months ago i am working on contract for a company.
I would like to know what kind of application we need to do to extend my husband's visa and what documents we require.

During these 5 years i was self employed but all my tax returns are showing no income as most of the time i was not working because of pregnancy then because of my father getting sick and having to look after him and my son. I have paid all my national insurance contributions during this time and I am now in full time employment.

What documents do we need to have to support my husband's application and what form do we need to fill? Do we need to wait until his visa expires to apply?

Thank you very much for your support.
Ally