You tap into this interpersonal network through Internet mailing lists and newsgroups. There are at least 100 genealogy mailing lists available via e-mail. Lists can be hard to find, but a comprehensive catalogue is available in Genealogy Resources on the Internet compiled by Chris Gaunt and John Fuller. The first 13 pages of this 79 page document contains a list of lists. You can subscribe to a list by clicking on its name and calling up your Web browser's e-mail form.
Lists can be very specific.
I confess to subscribing to one genealogy list, GER-RUS , which is about Germans who moved to Russia in the last century. The other subscribers are outrageously helpful. One Canadian has access to microfilmed church records, and will look things up for you. Newsgroups are similar to mailing lists. You access these through a news reader program such as Free Agent.