there are a lot of corporate research labs that are throwing millions into nanotech for various reasons.  ibm, intel, nec, hp, and samsung are some pretty big companies to name a few.  those are big companies that are researching heavily into nanotech.  
beside those companies, there are smaller startups sprouting up from the centers and academic institutions that are leading the research in nanotech-- i think one of the best labs is the program at harvard.  
and besides those, there are nanotech startups that are already public, i think the bulk of them specialize in nanomaterials.  
theres a lot of confusion and chaos though because people don't really know how to define nanotechnology.  some people say that its science that occurs at the nanosize.  If thats the case, nanotechnology really isn't anything new at all.  I think the first thing you should understand about nanotechnology is the confusion that comes from different people trying to define it.  
mit's tech review is a pretty good source of info.  
www.techreview.com.  they have a good section on nanotech.
besides that, there is 
www.nanotechplanet.com.  there are some other ones but i can't recall it off the top of my head.  
  EDIT: tried to fix some grammar