Who do I need to inform when making my own cycle event?

I am planning on making my own cycle event and want it to be quite popular in my area, where people will pay to join me cross england going through the yorkshire dales from Middlesbrough to Blackpool. But I wouldnt know where to start with concerns on whom I need to inform that I am doing it with the other participants. I am also unsure of any legislation I need to follow as I would be partly liable for the safety of the other participants. I hope someone can help. Thanks.