I recently was involved in a conference call with a prospective client who was asking me whether I would be available to come speak to their office meeting about how the staff could work closer with corporate HR professionals. I got off the call and began to look back to the time in my career when I was in the external recruiter's seat and what was important to me to establish that relationship.

So for what it is worth, here are my thoughts.

1. The Toyota Production System talks to us about GEMBA. It is a Japanese term for go and see. I fully realize that we are in tough economic times but it is worth the investment to take the time to go and see the client's operations. Meet face to face with both HR and the hiring managers. This is not a sales call this is a listening call. Find out exactly what their want and needs are. When I worked as a full time recruiter I had approached a Fortune 1000 corporation who loathed working with recruiters totally. I asked for a 30 minute meeting and went to his offices and met with HR and we talked about the Voice of the Customer as to what his wants and desires were. By listening to that conversation I became the only recruiter he would work with.
2. The recruiting profession does not have the greatest reputation out in the marketplace and one of the reasons is a lack of ethics. Respect that the client is paying your bills and treat them accordingly. Once again when I was working int he field, I was the VP of a firm and with the blessings of the President of the firm I sat down with the outplacement director of one of the largest Certified Public Accounting firms in the world and arranged that we would receive the name of all the staff that were not going to be offered partner as long as we did not poach the current staff from their clients. Went back to the office and explained this to an office meeting. Within a half-hour one of the banks did exactly what we said we would not do. The President of the firms comment when informed of the actions was that if you had any business ethics you did not belong working for the firm. We lost a source of good talent, a good client and a loss of reputation in the marketplace.
3. HR has a responsibility to their organization to find the right person for the right job at the right time and in the right place. As a recruiter you have the ability to assist in this goal by not weeding out talent for arbitrary reasons. Several years ago a recruiter posted on the Internet that she would not refer someone to a client who had grey hair.AH I HAVE BEEN GREY SINCE AGE 19. Nothing like implied age discrimination.While I know you want that check you also have the responsibility to let your client know when they are planning on taking action which might be deemed illegal.
4. HR has the responsibility to make it clear to recruiters what the skills are that are required for the positions but also need to make sure the recruiter understands the culture of the organization. A recent survey said that hiring managers are more likely to hire for culture fit rather than skill fit. One survey went so far as to say that they would more likely hire someone they could be friends with over whether the could do the job.
5. In #3 above we talked about the role HR has to play within the organization, but you have an equally important role and that is you nee to remind your client that unless someone truly misses the bona-fide occupational qualifications rule, the goal is no to rule them out but rather to rule them in. I fully realize that you want that check but that does not mean that you should tolerate actions which may be illegal. You have a vast readily available talent pool at your disposal, don't rule out those who are in a position due to no fault of their own.
6. HR needs to be sure that the position that they are recruiting for actually exists. It is unfair to the candidates, the hiring managers, the organization the recruiter and your organizational reputation be referring individuals to organizations for no reason.Likewise recruiters should not as a rule pitch candidates to HR or a hiring manager on the hope that there is a job available.
7. I do not know how you work individually, but i never stockpiled resumes. Each and every search assignment was conducted as a clean slate. I referred to those who were in my Rolodex but I never used them as the sole source of candidates. I also did not rule people out because of the status of their employment.
8. I have a business partner, Tony Alessandra, who suggests the way to success is through consultative selling. In order to add the value to the relationship the goal is for you and HR to work as equal partners in the process.Both of you will come out of it with a  win-win situation.