How can I start networking in another location in advance if I plan to relocate to that town or country?

Start with getting your CV on the Internet and by conducting job searches on the Internet for that specific area. If you belong to a club or professional organization, find out if they have representatives in that area. Contact those representatives and let them know that you are planning to move to the area. You may also let them know that you are looking for a job. Find a chat room via the Net for that area and start making contacts.