True Count

can anyone help me with these questions concerning the true count or give me a good internet site i could go to for answers:

1. is it really important in a single deck game to find the true count?
2. is the true count more for betting purposes, in which you would go back to the running count after you have made your bet or do you continue your running count from the true count?
3. in multiple deck games, when do you first want to find the true count (for example: after one deck is gone in a 6 deck game)