As an artist you should be aware of:

PRS

PPL(artist member)

MCPS (for sync and compilations)

and if you are going it alone without a label:

PPL(artist as label)

CatCo (chart elegibility)

I will be expanding on this very soon. It is definitely not as mysterious and hard as it sounds but you will have to fill in a few forms to collect royalties due to you.