I am looking for a book to study operator algebras: linear spaces, banach-, C*- and von Neumann-algebras, etc. on an introductory level for physics. After searching a bit it seems that "Operator Algebras: Theory of C*-Algebras and von Neumann Algebras" B. Blackadar should be a good choice. This is also the reference mentioned in the wikipedia article. Does anyone know this book? Any other suggestions?.. may be there are also some online notes somewhere?