Here are some of the websites I have found useful since my diagnosis:

Cancer support

Cancer support http://www.macmillan.org.uk

Breast cancer care http://www.breastcancercare.org.uk

Live better with cancer http://www.livebetterwith.com

Pregnancy and cancer

Supporting pregnancy through cancer http://www.mummysstar.org

Scalp cooling 

Scalp cooling http://www.paxmanscalpcooling.com

Life insurance

Life insurance made for mums http://www.polly.co.uk