Where can I find references that discuss important classes of Infinite Hopf Algebras. By important classes, I mean heavily used in research and of relevance to Hopf Algebraist(s),Physicists, Analysts(Real/Complex),..etc. 



References For Important Hopf Algebras 
[Shahn Majid](http://www.maths.qmw.ac.uk/~majid/Welcome.html)'s book *Foundations of quantum group theory* (Cambridge Univ. Press 1995, 2000) has lots of examples and of classes of examples. These are not only examples of quantum groups in the narrow sense (cf. the $n$Lab [page](http://www.ncatlab.org/nlab/show/quantum%20group) for other references on quantum groups in various senses). 


