Remember you will be doing this on a strictly voluntary basis, so don't list things that will take hours of research unless you are really willing to do it. Try to list items that aren't widely available to others and are of general interest to others. Databases that cover a particular area and not just your family. Listings that only give a place, but no specific items. People do not know what is available at these places.
Most people have a general idea what is at a county courthouse.
World Family Tree and the Social Security Death Index. I'll add these only if you also list some other items. There are FHCs all over and almost everyone has access to this. Due to the amount of time it takes to maintain the Helplist, I may not respond to entries that do not contain anything that I can add to the Helplist. Please remember that you cannot in any way profit from looking up the items you list.