Try some simple texts first:

Brewer, John D. (2000) Ethnography, Buckingham: Open University Press

Silverman, David (ed.) (1997) Qualitative Research - Theory, Method and Practice, London: Sage

Thank you Ron! =) 

A very handy book that I like to indicate is:

Schwartzman, Helen B. (1993) Ethnography in organizations California: SAGE Publications, Inc.

Thank you Carlos!! 

I am glad to hear that you are willing to explore the benefits of enthnography.  With prior degrees in engineering, I had always assumed that I would pursue only quantitative methods.  Then... I was exposed to qualitative research, and on recommendation of my dissertation advisor,  ethnography.  It was life changing.  

The best book on ethnography in my opinion is 

Murchison, J. (2010). Ethnography essentials. San Francisco, CA: John Willey & Sons.

Here are others (some are a bit older, but still good)

Borgatti, S. (1999). Elicitation techniques for cultural domain analysis, In J. Schensul, M. LeCompte, B. Nastasi & S. Borgatti (Eds.), Ethnographer's toolkit: Vol. 3: Enhanced ethnographic methods (pp. 115-151). Walnut Creek, CA: AltaMira Press.

Emerson, R., Fretz, R., & Shaw, L. (2011). Writing ethnographic fieldnotes (2nd ed.). Chicago, IL: University of Chicago Press.

Heyl, B. S. (2010). Ethnographic interviewing, In P. Atkinson, A. Coffey, S. Delamont, J. Lofland & L. Lofland (Eds.), Handbook of ethnography (pp. 369-383). London, England: Sage Publications.

LeCompte, M. & Schensul, J. (1999). Ethnographer’s toolkit: Vol. 1. Designing and conducting ethnographic research. Walnut Creek, CA: Alta Mira Press.

Schensul, J., LeCompte, M., Hess, G. A., Nastasi, B., Berg, M., Williamson, L., Brecher, J. & Glasser, R. (1999). Ethnographer’s toolkit: Vol. 7. Using ethnographic data. Walnut Creek, CA: AltaMira Press.

Schensul, J. & LeCompte, M., Nastasi, B. & Borgatti, S. (1999). Ethnographer’s toolkit: Vol. 3. Enhanced ethnographic methods. Walnut Creek, CA: AltaMira Press.

 Schensul, S., Schensul, J. & LeCompte, M. (1999). Ethnographer’s toolkit: Vol. 2. Essential ethnographic methods. Walnut Creek, CA: Alta Mira Press.

Smith, V. (2010). Ethnographies of work and the work of ethnographers, In P. Atkinson, A. Coffey, S. Delamont, J. Lofland & L. Lofland (Eds.), Handbook of ethnography (pp. 221-233). London, England: Sage Publications.

Wolcott, H. F. (2005). The art of fieldwork. (2nd ed.). Lanham, MD: AltaMira Press.

Wolcott, H. F. (2008). Ethnography: A way of seeing (2nd ed.). Lanham, MD: AltaMira Press.

For a foundation and really understanding the concept of ethnography I would recommend quickly reading Wolcott's Ethnography Lessons: A Primer.

Look up Wolcott's Stinky Kid.  You may have a moral reaction to how things transpired, but as far as being a leader in the ethnographic field,  it is hard to learn more than when one relies on Wolcott's readings.

Here's our annotated list from the chapter on ethnography in:

Iphofen, R.,  Krayer, A. & Robinson, C. (eds.) (2009) Reviewing and Reading Social Care Research: From Ideas to Findings

(A Training Manual with Support Materials) Bangor University (October)

ISBN 978-1-84220-120-6

Bryman, A. (2008) Social research methods (3rd ed.). Oxford: Oxford University Press. [This book includes a chapter on structured observations and ethnography and participant observation. Both chapters are very accessible and provide a useful introduction to observations. Sampling issues and validity and reliability are covered in each chapter.]

Delamont S. (2004) Ethnography and participant observation. In C. Seale & G. Gobo (Eds.) Qualitative research practice (pp. 217–229). London: Sage. [Delamont provides an accessible introduction to the issues of ethnography and observation. The book also contains a chapter on ethical issues in fieldwork.]

Hammersley, M. & Atkinson, P. (1983) Ethnography: principles in practice. New York: Routledge. [As the title suggests, a book that usefully explains how to put the theory into practice.]

O‘Reilly, K. (2008) Key concepts in ethnography. London: Sage. [This very accessible text covers and summarises the basic and related issues in ethnography. Many relevant examples from key ethnographies are included, as well as examples form the authors own research experiences and writings.]

Silverman, D. (2001) (2nd Edition) Interpreting qualitative data: methods for analysing talk, text and interaction. London: Sage Publications. [This is an easily understandable practical book which shows how data is analysed after it has been collected.]

Wow! Thank you so much to all of you!! Now I have a lot of literature to explore and look forward to my research project!! It's really kind from you! Best regards from Switzerland!