documentclass{book}
usepackage{totcount}
newtotcounter{bibitems}
newtotcounter{figure}
regtotcounter{table}

begin{document}
The total number of figures is total{figure}, and the total number of tables is total{table}.



begin{figure}
[...]
end{figure}

begin{figure}
[...]
end{figure}



begin{table}
[...]
end{end}

begin{table}
[...]
end{end}

end{document}

documentclass{article}
usepackage{totcount}

newtotcounter{citnum} %From the package documentation
defoldbibitem{} letoldbibitem=bibitem
defbibitem{stepcounter{citnum}oldbibitem}

begin{document}
This document contains total{citnum} references.

cite{Martin06} cite{Fortran2008}

begin{thebibliography}{1}

bibitem{Martin06}
P.~A. Martin.
newblock {em Multiple Scattering. {Interaction} of Time-Harmonic Waves with
  {$N$} Obstacles}.
newblock Cambridge University Press, 2006.

bibitem{Fortran2008}
Fortran standards technical~committee (J3).
newblock Fortran 2008 language standard.
newblock Technical Report J3/10-007, International Committee for Information
  Technology Standards (INCITS), 2010.

end{thebibliography}
end{document}

...
You've used 8 entries,
...

grep -P "You've used [0-9]+ entries," -m 1 "Document.blg" | grep -P "[0-9]+" -o

documentclass{article}
usepackage{bashful}
begin{document}
Foo...

bash[script,stdout]
grep -P "You've used [0-9]+ entries," -m 1 "Document.blg" | grep -P "[0-9]+" -o
END
end{document}

usepackage{totcount}
newtotcounter{citenum}
AtEveryBibitem{stepcounter{citenum}}