www.micahimages.com

Informational Forums (one of the best way to get current information on trekking is from active user forums)

http://www.indiamike.com/india/ (the best most well organized source of user generated information for travel in India including a trekking and mountaineering section)

http://www.lonelyplanet.com/thorntree/index.jspa (good source of information about budget travel covering the entire world)

http://www.yetizone.com/ (very good site on trekking in Nepal with forum and detailed online guides of treks in the Everest, Annapurna, and Langtang regions)

Online Maps

http://www.lib.utexas.edu/maps/ams/india/index.html?p=print (dated but detailed U502 map covering India and some of Nepal, one of the few maps you can find of the Indian Himalayas with contour lines)

Guidebooks

http://www.trailblazer-guides.com/books/ (A good guidebook series for independent trekking the Himalayas unfortunately they only cover Ladakh, The Everest Region, and The Annapurna Region, and there guides are getting dated)

http://www.cicerone.co.uk/product/index.cfm/menu/3/cid/32/catalogue/himalaya (The British company Cicerone specializes in outdoor activity guidebooks and has several good guides on trekking in the Himalayas including recently updated titles on Trekking in Ladakh (2012), Annapurna (2013), and Everest (2011).  These books are also available in ebook versions which can save a lot of weight when trekking.  On the cicerone website they are available in Adobe Digital eBook format which is compatable with Nook, PCs, and ipads (via Cicerone's ipad app).  Kindle users can now also get selected titles in the mobi Kindle format from amazon.com. )

Mountain Health and AMS

http://www.ismmed.org/np_altitude_tutorial.htm (Good review with accurate and detailed information about the symptoms and treatments of AMS)

Trek & Tour Operators

While this guide is about independent trekking I recognize some people like the security and easy of an organized trek.  Below are a list of my friends websites who work in the travel industry all of whose  websites I have worked on myself.  I do not guarantee that they will provide the lowest price, but I do know all of them  very well personally and vouch for their character.

Nepal:

http://www.highaltitudedreams.com/ (Kili Sherpa- High Altitude Dreams, specializes in organizing 8000 m expeditions, including Mt. Everest Expeditions, as well as other climbing expeditions throughout the Himalayas, and high end treks in Nepal)

http://www.sherpa-adventure.com/ (Lhakpa Gyalzen Sherpa- Sherpa & Swiss Adventures, organizes treks, expeditions, and tours in Nepal)

http://www.himal-adventure.com/ (Phurba Gyaltzen Sherpa- Himalayan Sherpa Adventures, organizes treks, expeditions, and tours in Nepal)

India:

http://www.trekhimalayas.net/ (Mohan Nepal- Trek Himalayas, based in Sikkim, organizes treks and tours in Sikkim, Nepal, Ladakh, and Goa)

http://www.clickladakh.com/ (Showkat Ali- Indian Himalaya Expeditions, based in Leh, Ladakh, organizes treks and tours in Ladakh)