what resources of information do you have on development of a small block of apartments please?

Other

I have recently purchased a very run down 7 bed HMO, I have planning permission application to change to 4 separate apartments, 3 x 1 bed and 1 x 2 bed. I intend to rent all 4 out long term, but may wish to sell individually in the future. There will be a small communal hall/entrance, each apartment with its own separate supplies and meters for gas, electricity, water and broadband. I would like advice on getting all the new required supplies, managing communal areas, and potentially renting/selling some of the apartments so management of a mixed unit, ie some I own and rent some tenants rent but I had some responsibility for the building as a whole.