Literature
It is very important to have a special Interrail-book with you. You will save a lot of time in searching nice places to sleep and were you can get a cheap meal. And you won't miss nice natural and cultural places you can visit. It is better to spent a littel bit more of money for a book and have a super holiday than to save the cash. You will miss a lot without it !!!
It is also very important to watch the books date of print. Older books are never needfull, because you will for example walk for an hour to go to a cheap hotel and then you remark that the hotel has disapeared. This would be very stupid I think.
Here are only german books presented. If you know a nice book in english or another language which is very good, tell me.
- Mit der Eisenbahn durch Europa

Michael-Müller-Verlag, Erlangen/Germany
the author is Eberhard Foher
this book is available in three parts.
North-Europe
Middle-Europe and
South-Europe
In this books you will everything you nee for your trip. The cheapest places to sleep, the nices places to get food and the best places you should travel too.
The price is between 22 DM and 27 DM one book.
- Interrail - Das Bahnreisebuch

rororo-Verlag/Germany
the author is Klaus Christian Wanninger
There are not so much special informations and hints in this book. Only big places are mostly presented, not so much small and nice villages like in the book before. But this is normal because here is all Europe in one book. Negativ is that often no prices are presented for hostels and food.
I think this book is interessting for someone who want to visit every country during this 4 weeks and who don't want to see every detail of a it.
The price is about 20 DM.