Reference to equations

In my opinion, for equations the best is to use \eqref{}.

How to use reference to page number

For good or bad, I extensively use \autoref from the hyperref package. Mainly because it's simple.

Well there's a command named \autopageref{} which replaces \pageref{} and does exactly what I wanted. More info here.

How to write parenthesis when referring to equation with \autoref

http://tex.stackexchange.com/questions/153496/combining-autoref-and-eqref

Correct autoref for user defined tags

To prepare the autoref package to user defined tags such that theorem or algorithm you can define the autoref name as described in:
http://tex.stackexchange.com/questions/46258/how-to-get-correct-autoref-for-theorems

How to make references to equations

To have correct references of the same form to the equations use the \autoref{} command from within the hyperref package. This will also creat hyperlinks within the document into the referred equations.