Andrea: There is a recent book that might help you with
  your difficulty with Giemsa staining. Here's a re-posting
  of a note I sent to the HistoNet lisserver a few months
  ago.
 
>   It is: Troubleshooting Histology Stains, by Richard W. Horobin
>   and John D. Bancroft. New York and Edinburgh: Churchill Livingstone.
>   pp. xvi + 266, with 36 colour plates. ISBN 0 443 05312 X. Needless
>   to say, both authors are well known and are authors of other
>   books in the field.
> 
>   A short introduction is followed by the coloured photos, which
>   illustrate tissues correctly stained by several methods. The
>   main part of the book contains accounts of 58 different staining
>   methods, in alphabetical order. Each account begins with 
>   background information about how the method works. This is 
>   followed by hints on avoiding problems (What types of specimen
>   processing are suitable? Is the procedure easy to carry out?)
>   and on dealing with problems that do arise (e.g. Staining
>   solution looks peculiar; Tissue stains unexpectedly
>   weakly; Unexpected structures stain). Each type of difficulty
>   is explained, with instructions for putting it right or avoiding 
>   it next time. There are references in the text, a 10-page
>   bibliography, and also a list of references to books that give 
>   practical instructions for all the methods considered. 

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1