The University of Wisconsin's online microbiology
textbook, is a usefull reference to study all aspects of Microbiology:

http://www.bact.wisc.edu/Microtextbook/

Another free online Microbiology Textbook:

Medical Microbiology

Here is another online textbook:


http://www.textbookofbacteriology.net/

hi there


trook,Richard Taylor,Soudabeh thank u these are good and useful for the people