I want share a bit of my experiences with the Indian trains. The train system in India is quiet good. You can travel the whole, gigantic, country by train. (going from Delhi to Trivandrum e.g. from north to south will take about 48 hours) It is fairly cheap, even in the better classes. I paid about 45€ for more than 800km in A/C 2 Tier Class on Tatcall (Emergency Tickets, which are sold at a certain time, are not refundable and a lot more expensive than the usual ones), going from Kochi (Cochin) in Kerala to Madgaon (Margao) in Goa. Although the trains are named “Superfast”, and “Superfast Express”, which is a bit faster, they are not that fast by western standards. With the Superfast Express it took about 14 hours for the 860km from Kochi to Madgaon. (btw: this is just an example, I took trains several times during my vacation in India and the best one by far was the 7:00am train going from New Delhi to Aggra)
But, infrastructure in the trains is great, and vendors are passing by every 5-10 minutes offering you food and tea/coffee you can buy (at very reasonable prices). If I were you, I would avoid ordering the food the railways company sells. Once you boarded, an employee of the company will come to your seat/bed, if it’s an overnight train he will bring you sheets and a pillow. If the railway company sells meals, someone will go around taking the orders. I ordered vegetable Biryani, but I found it to be rather dirty and bad quality. However, I’m sure you will know for yourself if things are safe to eat or not.
I would always try to book the highest class available, especially on train rides for several hours. All A/C classes looked fine to me, but the Sleeper classes were rather dirty, at least to sleep in.
Keep in mind that the A/C classes can get relatively cold, so bring enough clothing. Long pants, a pullover and a scarf are not too much, in my opinion. When in very crowded places I sometimes liked to cover my head with the scarf. Prevents the omnipresent staring. In general, especially when you are backpacking in India and will use local busses and trains, I recommend women to dress accordingly. No tight clothes, no clevage and at least the shoulders covered.
So, make yourself comfortable and enjoy the ride!
PS: Unfortunately, I did not take any pictures of the trains nor trainstations.