For somethings you can just set an option/toggle to change the formatting. There is a nice explanation in this question. Moving the date is not that simple. There currently is not a WYSIWYG editor for biblatex styles or even a system like makebst so your best bet is to find an existing style that meets your needs (or change your needs). If you really want to do it, you could redefine a bunch of macros in the preamble, but it will be much easier to create your own style.
Starting from standard.bbx you would need to redefine all the bibmacros which have "date" in their name like
\newbibmacro*{publisher+location+date}{%
\printlist{location}%
\iflistundef{publisher}
{\setunit*{\addcomma\space}}
{\setunit*{\addcolon\space}}%
\printlist{publisher}%
\setunit*{\addcomma\space}%
\usebibmacro{date}%
\newunit}
to be
\newbibmacro*{publisher+location}{%
\printlist{location}%
\iflistundef{publisher}
{\setunit*{\addcomma\space}}
{\setunit*{\addcolon\space}}%
\printlist{publisher}%
\newunit}
and then replace the references to the date version with the no date version. This will get rid of the date at the end of the reference.
Adding the date to the beginning of the reference requires adding
\usebibmacro{date}%
\newunit\newblock
to each BibliographyDriver in the appropriate place. For example, for books
\DeclareBibliographyDriver{book}{%
\usebibmacro{bibindex}%
\usebibmacro{begentry}%
\usebibmacro{author/editor+others/translator+others}%
\setunit{\labelnamepunct}\newblock
\usebibmacro{maintitle+title}%
\newunit
would become
\DeclareBibliographyDriver{book}{%
\usebibmacro{bibindex}%
\usebibmacro{begentry}%
\usebibmacro{author/editor+others/translator+others}%
\setunit{\labelnamepunct}\newblock
\usebibmacro{date}%
\newunit\newblock
\usebibmacro{maintitle+title}%
\newunit
style=authoryear. – Sverre Jan 25 '13 at 19:55