The Amicus Foundation is doing work in Bhutan and could do with support. The Bhutan Women’s Project support(s) cultural institutions that provide women a basic education, while passing on the spiritual traditions of their culture and needs another US$29,000 and any contribution can help. Other projects in education and culture are listed here.
UNICEF is helping to educate kids living in difficult circumstances [Details and how you can help]
If you know of any other NGOs doing work in Bhutan please send me an email. You could also put this link on your blog and generally spread the word around.
Disclaimer: I do not have any personal involvement, knowledge or experience with the organisation listed above