I would like to know the best one or two books that properly describe
the various ethnic tribes of northern Vietnam.  I am looking for
historical information...pre-history migration patterns up to how the
tribes lived during the French colonial times are a requirement.  More
recent history would be nice but is not a requirement.  The books can
be in or out of print, but should be in the English language.

Hello John080449,
I have rounded several titles on the Internet that may satisfy your
needs. They are more on all the tribes of Vietnam aside from just
Northern tribes, but they will most certainly have the history that
you need. I'll just put asterisks on the books I think are the best,
to narrow down the choices:

* University of Washington Press: Population and Ethno-Demography in
Vietnam by Khong Dien - $30
http://www.washington.edu/uwpress/search/books/KHOPOP.html

* Ethnic Minorities in Vietnam; New Edition (Select Books) - $16.50
http://www.selectbooks.com.sg/titles/14823.htm 

The Yao, The Mien and Mun Yao in China, Vietnam, Laos and Thailand
(Select Books)
http://www.selectbooks.com.sg/titles/31190.htm

Other works on Vietnamise/Southeast Asian ethnic groups:

Indigenous Peoples and Protected Areas in South and Southeast Asia:
From Principles to Practice (Select Books) - $21.19
http://www.selectbooks.com.sg/titles/29967.htm

Various books in English on Vietnam
http://www.cikadenet.dk/vietnam/Books_in_english_on_vietnam.htm

Another list of books in Vietnam (here with works on ethnicities)
http://www.thailine.com/lotus/vietnam/vietnam.htm
- I suggest: 
* Abadie, M. Minorities of the Sino-Vietnamese Borderland with Special
Reference to Thai Tribes, $22.50

Asiabooks list on Vietnam topic, A-C
http://www.asiabooks.gil.com.au/catalogue/vietnam_01.html

Google search strings:
tribes vietnam migration
ethnic vietnam book/books
tribes vietnam book/books

I hope the books you need are among these. Regards.

Here's one book which may/may not come in handy, I'm no good with
Vietnamese/French colonial history...

http://www.amazon.com/exec/obidos/ASIN/9747534576/qid%3D1048471925/sr%3D11-1/ref%3Dsr%5F11%5F1/102-6959471-7455367

skermit-ga