I've been part of projects to migrate to BW on HANA recently and one of the things that I noticed was that resources can be fragmented and tricky to find. I thought I'd curate a list of places to go to find information. If I have missed something then please ping me so it can be added to here.
Since I've written this, I've realized that there is a lot of information out there, which may be overwhelming. I do encourage though, if you are planning a BW on HANA migration, that you take a look at this information before you build out your plan. You will be much better informed and I have no doubt that you will change your plan for BW on HANA.