Here we'll look at some key relationships between things you'll be able to configure in the administrator area (there are others, but these are the things you should do first).
Properties (AKA Businesses)
Firstly, let's look at Properties. Within the Jomres documentation, These are synonymous with Properties (eg Hotels, villas) because Jomres' roots are as a hotel booking system.
Properties can be defined as either MRPs or SRPs. If you're renting out the entire property (for example a villa or a yacht) then the property is an SRP. If you're renting out resources in that property (eg. rooms or boats or cars) then the property is defined as an MRP.
As a Site Administrator, you do not create businesses/hotels. This is done on the public facing pages, and is dealt with elsewhere in the documentation. At this point, all you are interested in is setting up an environment where properties can be created on the system.
Property types are one way to classify properties. A property can be a hotel, a car, a B&B or something else. In Jomres you can have property type specific language strings and template files. Property types can be searched upon through the various search features built into Jomres.
A property feature can be assigned a name, description and icon (you can upload icons via the administrator area Settings > Media Centre ). A feature can be assigned to specific business types, in which case other business types will not see those features as options in the business details edit page. If your property is a hotel, for example, then you'll be able to use the existing features and icons that Jomres creates for you when it installs. If it does not, then you may need to create some yourself.
Room types (AKA Resource types)
Regardless of whether the business is an MRP or an SRP, when you use the booking functionality of the system, you're booking out resources. Resource types are defined by the Site Administrator, because it is possible to search on a resource type when looking for a business. When a resource type is created, it can be associated with one or more property types, and it can be configured to be visible to only MRPs or SRPs.
When a business manager configures their resources, they associate the resource with a resource type. Next, they'll create tariffs for those resource types. This gives us a many -> one -> many relationship, allowing us to have, for example, many rooms of type A, and one tariff that sets the prices for all resources of type A.
Don't panic if you don't understand all this, it will become clear in time.