my partner has recently purchased a house, he has asked me and our daughter to move from our council house and live with him, how do we go about adding my name to mortgage/deeds
First instance contact the lender, if they are any good they will tell you all you need to know. Only add your name if you are going to contribute to the mortgage and then ensure a payment schedule is agreed so that if were to split up, any share you have in the house, by helping with the mortgage, is properly documented and thus easily resolved. Good Luck :-)
Ensure you go into this with your eyes wide open, putting your name on the mortgage makes you laible for the debt, in simple terms. Money and relationships are very hard to balance, please tread carefully, recommend you take independent legal/financial advice.
As well as the potential financial problem of mortgage payments if the relationship breaks up, you could also have housing problems. You presumably have a secure tenancy in your council house. If you give this up to move you could have difficulty getting re-housed.