You can create a resource in the right-side toolbar, under the “Resources” tab, or by double-clicking on the task to open Task Properties. Once you are under “Resource”, you can name the resource and pick a resource type. A type of resource could be a “Worker” or “Material”.
Once you have created the resource, you can then assign it to the task. 
If the Resource is a material such as a “paint bucket”, you can change the units needed to complete the task from one to more units.