Faculty/Staff Transactional Services
To determine the best resource for faculty and staff HR/payroll/employment issues start with this question: Is this a system-, campus-, or college-level issue?
CU System (in Denver on Grant Street), specifically Employee Services, always has websites and email addresses with cu.edu as their domain. System sets policies and determines resources that apply to all four campuses, such as insurance coverage, benefits, etc.
Boulder campus HR implements those system policies, but specific to the Boulder campus. So, you may find some information to be intertwined. For example, the tuition assistance benefit is set by System since it's available to employees on all four campuses, but it is implemented in specific ways by each campus. Which means you will find some information for this benefit via sites and emails with cu.edu (System) and some information via sites and emails with colorado.edu (Boulder).
Analogously, HR/payroll/employment processes set at the Boulder campus level may have their own variations set by the specific college, school or program within the Boulder campus. For example, faculty affairs issues are guided by the Office of Faculty Affairs for the campus, but the College of Arts and Sciences' processes and policies vary from those in Leeds, ENVD, and others.
Whenever in doubt, start by consulting your Program Coordinator. For more complicated issues such as leaves of absence, you'll likely need to work with your dean's office, too. HR/payroll/employment issues are complex and the university structure is complex, so getting to a solution is always a team effort.
Employee Services (System)
HCM Community (System), specific page for the HCM software/portal
Human Resources (Boulder), main page
Human Resources (Boulder), benefits and perks list
Human Resources Guidance Library (Boulder), A-Z, gives contacts and links to policies, etc.
HR Service Center (Boulder), not all colleges use the HRSC; the Program Coordinator will know if this is an appropriate resource for your program
FSAP (Boulder), Faculty and Staff Assistance Program; this is the resource for free counseling services for faculty and staff; note the link at the bottom right to report concerning incidents (similar to student case management)