Workflow should come with a generated resource library loaded by default in each project (Symantec.Components.Generated7.Altiris.Resource). This resource library introduces components like Get*ByID and GetAll*, where the * are various resources. If you don't find the specific resource you want to use, you have to "regenerate" the library by double-clicking on the project in Workflow Manager and running the wizard against the SMP you're going to use.
These components come as-is, and it's important to note that they're generated by running against the NS Web Services solution on the SMP. I'd consider them "advanced" components.
There is also a library called Symantec.Components.Resource7 (loaded by default) that introduces higher level components, like Get Resource, Get Resources, and Save Resource. These components depend on the generated library mentioned above to provide different resource types to fetch. If you don't see the resource type you'd like to fetch, you have to regenerate the generated library mentioned above. These components are actually handcoded, and aren't generated like the previous library above.
When you use either of these 2 libraries, you need to use a Create SMP Credentials component (pointing at the SMP you want to use) before using a resource component afterwards.