It is so simple. When you want to purchase anything from Amazon go to Amazon Smile instead by clicking here. Log in using your Amazon password and select Macmillan Caring Locally from the list of charities. Bookmark the page for future use, and away you go.
For every purchase you make Amazon will donate a percentage to our charity, and it has cost you no more than if you were buying from the usual Amazon site. Over time you will see on the Amazon Smile page how much you have kindly generated for us.