Consolidated list of Indian Railways Websites

Disclaimer : I am not responsible for the authenticity of the below information. Views expressed are personal only.

Websites for choosing train

Indian Railways Trains & Stations - http://indiarailinfo.com
One of the best sites available to search for trains. It includes average delay of the train, current location in the map. The interface takes a little time to get used, but once you get comfortable, it is very easy.

Indian Railways Timetables, PNR, Route fares etc - www.erail.in
Undoubtedly the simplest interface, it takes only 10 seconds to fetch any information for a given date and stations.

Indian Railways Rediff - http://indian-railways.rediff.com/index.php
A rediff approach .Quite friendly for those who are used to flight fare search :)

90 Degree Internet - www.90di.com
Very useful if there is no direct train available. Suggests itineraries with train hops. We can include flights as well.

Websites for Booking Tickets

Indian Railway Catering & Tourism Corporation ltd - http://irctc.co.in
Railways Official Site - India's busiest e-business site. Period. Ticket reservations to be made here only. The above sites are useful for planning only. Apparently, we could also install IRCTC software in phone with GPRS connection which lets us query PNR, book tickets, train search etc. have not tried personally.

OxiRail - www.oxirail.com
How to use:
1) Register your mobile number in OxiCash
2) Recharge the account like mobile wallet in OxiCash and
3) Use this mobile wallet to book the ticket in OxiRail

Advantages:
1) You can save the order before 8.00 AM (Before tatkal window opens) with train and all passenger information
2) The transaction processing here is also simple, so won't take much time to process the transaction (in irctc.co.in we need to go through more than three screens in the transaction)
3) No error like Connection refused/lost, click once and the transaction
will be completed (some time, takes time)

Drawbacks:
1) Sometime, transaction will fail, but still ticket will be booked after
two three minutes(You will get the message)
Tip: Keep exact balance to book only one ticket, in case of failure and retrying many times.
2) Rs10 extra as OXiRail charges

Other Railway Websites

Train Running Information - www.trainenquiry.com
Railways Official Site - this lets you spot any train right now.its says which stations it has crosses and how much late it is running LIVE! I use it when I am waiting for guests coming by train.

South Central Railway - http://www.scrailway.com/
Railways Official Site - Specialized for SCR Division under which majority of AP falls.

Hyderabad & Secunderabad MMTS Timetable - http://www.scrailway.gov.in/mmts/mmtstable.php
MMTS Timetable for local trains running in Hyderabad and Secunderabad.

Websites for Fun

IRTS - The Abode of Indian Railways - http://www.indianrailwaysimulator.com
If you are interested in playing train games :-D