don't say anything if puppy has an accident inside and you didn't catch it in the act (it teaches them to get attenion that way). You can get a spray ("housetrainng" I think - i got it from pets at home) which you spray where you want him to go (it stinks btw) but seems to work, and if puppy keeps going back to a particular spot inside you can spray some vinegar there.

There are charts in books about deveoplment that say roughly how many times your puppy will need to go, and that helps a bit.

Also learn your puppys body lang, ours has a little sniff and does a little dance before he goes.

Hope that helps and good luck!