This is a very interesting system which I discovered only this year.
In America all Libraries do this service free of charge. So only thing is you have to member of one of Libraries around. This is mostly possible if you are a student ,then you become member of your university library.

There is this very important website which may be useful for any one around the world
http://www.worldcat.org/

This is website lists which ever library(any where around the world) has the book of your interest. Just search for the book, when results come click on the book you want and type in your pin code in the following page. It displays all the libraries near you which has this book.

So the details you need for interlibrary loan is
Author
Title
Publisher
ISBN/OLC
Call number
Additional information like which library it is Available can be very useful.

In my university there is separate website called Illiad for inter libaray loan and I think Illaid should be the website maintainer for Inter library loan for many universities.I just have to fill up a form with above details. Most probably with a week or two I will receive all the books.

There are two options to collect the book either it will be mailed directly to your house or you can collect it from you library. I prefer collecting from the Library and returning is very simple if you collect it from your library, you just have to drop the books in your library before due date.

The books usually have due dates within 2 weeks and you cannot renew it. But you can reapply for it. 2 Weeks gives enough space for me to scan the book. So I scan the book and read it when ever I want.

Also there is no limit on number of books you apply for.

This system is fully operational in all university libraries.
I hope system like this comes up in India.

It is so easy to attain knowledge if you can easily access the source!

Regards,
Vairam