Can anyone give us tips on travelling south from Chennai by train & bus? Can we turn up at a station and buy a ticket without too much hassle? What is bus travel like? What is accommodation like - should we use hotels or is it OK to use guest houses, B&Bs, home stays etc and if so, should we take care what we eat & drink? Any advice on this would be very welcome.

i 2 am off 2 the south jan/feb/march

went to north last year rail is best booked a day before and is quite difficult watch out for theives all the time!
buses are easy but a bit uncomfortable and usually want your bags on the roof!
guest houses are fine even better is going to tourist board office where they will organise a homestay which is f**king brilliant
eatnearly what you want steer clear of salad water and ice peel fruit and buy bottled water available everwhere, i had chicken in a restaurant and got food poisoning for days very ill but that might have beeen just unlucky!

let me know if you need any more help!