Hi Serenity4
Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is.
Welcome to Benefits and Work It would depend on how temporary your family come to live with you, if they present themselves as homeless then they would get rehoused quicker, I would advise your family to contact Shelter 0808 800 4444 for advice and also your family needs to contact their local authority.
In regards to yourself, if your family come to live with you then if you are in receipt of SDP this may be affected and I would advise you to contact DWP and let them know what is happening otherwise you may be hit with an overpayment.
Gary