Here are some vetted charities that are providing services in Nepal. All of these are tax-exempt organizations. Many companies including mine match any donations to 501c to a certain amount usually $500-$1000. I think it is a great idea to use this offer and get your company involved too so the amount of donation can double. If someone wants to help but their company does not match charitable donations, see if you can find a friend who works for a company that does it and give him/her the money (just an idea).
CARE: 90% Program Activities, 10% Support and Fundraising
https://my.care.org/site/Donation2;jsessionid=4D30C91B2F7352751FE014D40115C447.app337a?18840.donation=form1&df_id=18840
Red Cross
https://www.redcross.org/combined-donate?donationProdId=prod9150029&campname=donateNepalEarthquake&campmedium=aspot_dis16
Oxfam
https://secure2.oxfamamerica.org/page/content/nepal_earthquake/
International Medical Corps
https://internationalmedicalcorps.org/nepal-earthquake-donate