Indeed i am now trying to read a series of papers  written by Einsiedler,Lindenstrauss,Michel and venkatesh that study distribution of periodic torus orbits on homonegeous spaces. They make heavy use of automorphic L-functions, and eisenstein series on adelic homonegeous spaces,but i almost know nothing about that.
  And it seems that many books on automorphic forms are quite involved and have too many pages for me. So I want to ask whether there some concise books that contain things about automorphic L-functions,eisenstein series on adelic homonegeous spaces. 
  Thanks for your attention.