Why did Voldemort wait a year after Harry and Neville were born?

[mariofett1187]

No: HPFGUIDX 99627

First of all, why did Voldemort wait a year? He knew the baby would 
be born on July 31st that year, and he must have been rather eager to 
kill the one that threatened him, so why didn't he attack the 
Potter's right away? 

Two related questions:

1) Why did he attack Harry and not Neville?

2) Why was the Fidelius chamr only put on the Potters a week before 
the attack? Did they have some kind of warning that Voldemort would 
be coming soon?

"mariofett"