Okay, now I'm with you. Answer is, it depends on the specific problem. On Legal issues I go to SHRM.org, since I'm a member, they have some good white papers; and I will also , wait for it...., read the regs. Legaleze is nasty but necessary. On some issues I rely purely on experience, do it for a while and you get the hand of it. Some things I talk with colleagues or mentors about it.
I tend not to blog on specific issues, thinking general topics are more informative, but that could change. Google is my best friend, networking is huge, just got back from a hr workplace excellence expo, so I guess you could say I do a bit of it all.
Thank you. I still find the question to be very broad. When you say Human Resources you're talking about a very broad field: Legal issues, Compensation and benefits, Staffing, performance management, Org Dev & training, and so on and so forth. Each of these major subject areas could easily have a top 5 list.
But in general, from the network of people I speak with, we are all seeing employment of qualified candidates as the #1 biggest challenge. This would include sourcing and retention related issues.