Organizations you probably belong to already - or perhaps should
AIMMGM: Asociación de Ingenieros de Minas, Metalurgistas y Geólogos de Mexico A.C. This is like the AIME of Mexico and the largest aorganization of professional mining engineers in Mexico. They are responsible for the Acapulco Convention held every two years in October.
SEG: Society of Economic Geologists whose periodicals include the industry standards: Economic Geology and SEG Newsletter.
SGA: Society for Geology Applied to Mineral Deposits. Sort of a European counterpart to SEG. Publishing forum is Mineralium Deposita.
MDSG: Mineral Deposits Study Group at the Royal School of Mines, Imperial College, London. Home base of the "geo-mineralization" list server and electronic entry point for economic geologists.
GSN: Nevada Geological Society: Dudes throw a good monthly fiesta in Reno with geological speakers that occasionally talk about their Mexican Projects. (Face it most of them are working south of the border anyway). .
AGS: Arizona Geological Society: Based in Tucson, this venerable organization is also sometimes referred to as the "porphyry posse" since this is from whence the majority of the members came. Good monthly meetings, talks etc. Outstanding publication series.
AMSAC: Asociación de Mineros de Sonora A.C. - An association of mining companies, industry service providers and business professionals focused on developing all aspects of the mining industry in Sonora, Mexico. Cia. Minera Cascabel S.A. de C.V. is a participating member of this organization. Very informative website (in Spanish).
SME: Society for Mining, Metallurgy and Exploration whose monthly publication is Mining Engineering.
GSA: Geological Society of America. 'Nuff said.
GSC: Geological Association of Canada. Good publications on ore deposits models among other topics.
AEG: Association of Exploration Geochemists. Based in Canada, this International Organization's publishing vehicle is the Journal of Exploration Geochemistry.
AGI: American Geological Institute - Home of GeoRef which has had it's new Preview Database up since last August.
AGU: American Geophysical Union. Good for stuff on Mars and the other planets or even occasionally our own planet (but usually at depths you could never afford to dig to.)
ILLGM: International Liason Group on Gold Mineralization is a non-profit world-wide group coordinated by Dr. R.P. Foster in Southampton, UK. (Website still needs a little work but here is where it will be!)