Hello friend,
This is a very good initiative and not an easy one!
1. You need to identify who you would like to talk to - will you choose someone randomly - or would you have a structure to select a person for this talk? Alternatively, you may send an email informing about the initiative and invite people to send their interest in talking to you as a representative of HR. This will help start the process.
2. I personally feel that you may prepare a list of questions on certain topics, and as you start the discussion, it may happen that the person himself wants to say many things not necessarily as per your agenda. In such a case, you have to continue to listen to him and note down the issues he has put forth.
3. Most of the time, you will need to play a "listener's role." This is not an easy one - you should only give him clarifications in case he is not aware of certain policies, etc. Otherwise, you need to respect his feelings and viewpoint. You need to understand the underlying message.
4. I feel that there is no need to conclude anything in the same meeting as some issues will need to be deliberated at various levels - so you should give an assurance that the opinions and suggestions will be considered.
5. If there is something that needs urgent attention, you need to inform your superior in HR - who could make some fast decisions in consultation with top management.
6. As I said, there is no need to look for a standard format - let the process start; it will evolve.
7. Generally, such a role of Listening Post is played by a Senior Management officer; however, if HR is starting the initiative, it is a good step.
8. Senior and Top Management should be willing to work on feedback given by you from these sessions - if that does not happen, then slowly people will not come to you as they would not see any value addition from such sessions (rather it may adversely affect the image of HR and personally you). So continue to work towards getting commitment from seniors for action on issues that surface in these meetings. Even if 10-15% of issues are addressed, it is a great success for HR.
Wishing you the best for your initiative - I am sure it will help improve employee engagement levels and also build a solid image of HR.
Regards,
Nishikant