There are comprehensive manuals available for Bentley OpenBuildings Energy Simulator.
The online help manuals can be found here.
The easiest way of accessing the manuals via the software is to simply press F1.
You can also access the manuals by going to File > Help > Help Contents. At this location you can find additional resources such as links to the Bentley Institute for training and to the OpenBuildings Communities page.
Note the software will automatically open an Online copy of the manuals in your internet browser. Should you wish to instead view the local copy (e.g. if you have no internet connectivity) please change this at File > Settings > User > Preferences, as below: