Covered Patio floor . Wood over concrete

[Jim littleton]

I would like to build a good sub floor over my concrete covered patio slab. 1 st so I can enclose the patio to make an outdoor room and 2 nd. So I can put a good non-slip surface on it. This room will be out my back sliding door and leads to my built in pool area. What type of prep will I need to make , such as ... Moisture barrier , type of wood etc. .... I have more questions but, I think i'll start with this. Thanks ahead of time for any insight you may provide.