I need your help in creating the following figure in tikz. I am absolute beginner in tikz.

I saw the example in the following page, but I need it the way as shown in the picture which I could not produce TikZ: Using Loop to Draw Grid of Nodes
I need your help in creating the following figure in tikz. I am absolute beginner in tikz.

I saw the example in the following page, but I need it the way as shown in the picture which I could not produce TikZ: Using Loop to Draw Grid of Nodes
Perhaps this code can help you. It's not possible to apply the code from your link because we don't know if the position of the arrows are automatic or not. A large part needs to be draw by manually. The next code is not very elegant but you can try to do something better. A fine idea is to determine the coordinates of all the nodes before drawing the grid with a loop like in the link without define nodes (only coordinates.
\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[
down/.style={path picture={
\draw[->] ([yshift=-3pt]path picture bounding box.north)
-- ([yshift=3pt]path picture bounding box.south);}},
up/.style={path picture={
\draw[->] ([yshift=3pt]path picture bounding box.south)
-- ([yshift=-3pt]path picture bounding box.north);}},
every node/.style={circle,draw, minimum size=1 cm}]
\node[label=45:$1$,up] (n-1-1) {};
\node[label=45:$2$,down] (n-1-2) at (2,0) {};
\node[label=45:$3$,up] (n-1-3) at (4,0) {};
\node[label=45:$n$,up] (n-1-4) at (6,0) {};
\node[label=45:$n+1$,down] (n-2-1) at (0,-2) {};
\node[label=45:$n+2$,up] (n-2-2) at (2,-2) {};
\node[label=45:$n+3$,down] (n-2-3) at (4,-2) {};
\node[label=45:$n+4$,up] (n-2-4) at (6,-2) {};
\node[up] (n-3-1) at (0,-4) {};
\node[up] (n-3-2) at (2,-4) {};
\node[down] (n-3-3) at (4,-4) {};
\node[down] (n-3-4) at (6,-4) {};
\node[up] (n-4-1) at (0,-6) {};
\node[down] (n-4-2) at (2,-6) {};
\node[up] (n-4-3) at (4,-6) {};
\node[down] (n-4-4) at (6,-6) {};
\foreach \i [count=\xi from 2] in {1,...,2}
\foreach \j [count=\xj from 2] in {1,...,3}
\draw (n-\i-\j) -- (n-\xi-\j);
\foreach \j [count=\xj from 2] in {1,...,4}
\draw[thick,dotted] (n-3-\j) -- (n-4-\j);
\foreach \i [count=\xi from 2] in {1,...,3}
\foreach \j [count=\xj from 2] in {1,...,2}
\draw (n-\i-\j) -- (n-\i-\xj);
\foreach \i [count=\xi from 2] in {1,...,4}
\draw[thick,dotted] (n-\i-3) -- (n-\i-4);
\draw (n-4-1) -- (n-4-2) (n-4-2)--(n-4-3) ;
\draw (n-1-4) -- (n-2-4) (n-2-4)--(n-3-4) ;
\foreach \i in {1,...,4} {%
\draw (n-\i-4)--++(1.5,0) ;
\draw (n-4-\i)--++(0,-1.5) ;
}
\end{tikzpicture}
\end{document}

To do something perhaps better. I removed a large part of the code. Your problem now is to draw the vertices and the arrows inside the circles. I wrote all the labels to help you if you want to designe some nodes
\documentclass{minimal}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[darkstyle/.style={circle,draw,minimum size=10mm}]
\foreach \x in {0,...,4}
\foreach \y in {0,...,4}
{%\pgfmathtruncatemacro{\label}{\x - 5 * \y +21}
\node [darkstyle,label=45:$n-\x-\y)$] (n-\x-\y) at (2*\x,2*\y) {};}
% \foreach \x in {0,...,4}
% \foreach \y [count=\yi] in {0,...,3}
% \draw (n-\x-\y)--(n-\x-\yi) (n-\y-\x)--(n-\yi-\x) ;
\end{tikzpicture}
\end{document}

\node [circle,draw,inner sep=1pt] {$\downarrow$};. – Peter Grill Apr 16 '13 at 17:54