Newbie question: what is the typical and extreme values (excluding +/-infinity, and are these used too?) that can occur in training/running of NNs? Also, what l

Newbie question: what is the typical and extreme values (excluding +/-infinity, and are these used too?) that can occur in training/running of NNs? Also, what level of accuracy is needed? It may well be a stupid q but I really don't know, and always assumed they would be [-1..+1] and that fixed point would suffice. Clearly not.