If you decide to do the staying with relatives route, make sure you get mail sent to both you and your husband at that address for the time you live there. There's suggestions on what to get sent and how in the Visa and Citizenship section. It won't be as simple as you won't be paying utilities, but you will need it for your ILR. I know my husband's bank won't put my name on his accounts until we go in with a piece of mail with my name and address on it, so you could try to start getting things sent there now to open your bank accounts. I don't know anything about a guarantee, but if there is one, I am sure someone can explain it to you.