I would like to draw the following E-R diagram:

I am using the TikZ-er2 package. The package is available here. Now, I have completed almost 50% of the drawing. But, my TikZ picture appears in page 2 (article class and I have put landscape mode) and when the diagram is extended, it cuts off. How do I proceed? And I want to label my drawing as well. I can have a separate node for that, but are there any other ways.
Here is what I have done:
\documentclass[12pt]{article}
\usepackage{tikz-er2}
\usepackage{lscape}
\usetikzlibrary{shadows}
\begin{document}
\tikzstyle{every entity} = [top color=white,bottom color=blue!30,draw=blue!50!black!100,drop shadow]
\tikzstyle{every attribute} = [top color=white, bottom color=yellow!20,
draw=yellow, drop shadow]
\tikzstyle{every relationship} = [top color=white, bottom color=red!20,
draw=red!50!black!100, drop shadow]
\tikzstyle{every edge} = [link]
\tikzstyle{every isa} = [top color=white, bottom color=green!20,
draw=green!50!black!100, drop shadow]
\begin{landscape}
\begin{tikzpicture}[node distance=10em]
\node[entity] (student) {Student};
\node[isa] (isa1) [below of=student, node distance=5em] {ISA} edge node [auto,swap] {disjoint} (student);
\node[entity] (mtech-stud) [below left of=isa1] {MTech$-$student} edge (isa1);
\node[attribute] (btechproj) [below left of=mtech-stud] {No.-of-BTech-Projects} edge (mtech-stud);
\node[entity] (btech-stud) [below of=isa1] {BTech$-$student} edge (isa1);
\node[entity] (phd-stud) [below right of=isa1] {Ph.D.$-$student} edge (isa1);
\node[attribute] (stud-id) [left of=student] {\key{student-id}} edge (student);
\node[attribute] (name) [above left of=student] {Name} edge (student);
\node[attribute] (fname) [above left of=name] {First-Name} edge (name);
\node[attribute] (lname) [above right of=name] {Last-Name} edge (name);
\node[attribute] (cgpa) [above right of=student] {CGPA} edge (student);
\node[relationship] (joins) [right of=student] {joins} edge [total] (student);
\node[entity] (pgroup) [right of=joins] {Project-Group} edge [<-] (joins);
\node[attribute] (group-id) [above left of=pgroup] {\key{group-id}} edge (pgroup);
\node[derived attribute] (group-cgpa) [above right of=group-id] {group-CGPA} edge (pgroup);
\node[multi attribute] (areas) [above right of=group-cgpa] {areas-of-interest} edge (pgroup);
\node[relationship] (pgroup-guide) [right of=pgroup] {Project-Group-Guide} edge (pgroup);
\end{tikzpicture}
\end{landscape}
\end{document}


tikzstyle, buttikzsetfor your styles. Second: have a look to How to scale a tikzpicture including texts?, How to scale a tikzpicture to \textwidth and pgfplots: how can I scale to text width? – Claudio Fiandrino Mar 08 '14 at 09:04