she has to receive an eductation, not necessarily school, from the term after she turns 5 - ie Jan 2011. In reality being one of the eldest in the year she will start in Sep 2010.
the council will have the procedure, different LEA's have different deadlines - ours is late Dec for the following Sep, others are later, some are earlier.
Our council you can apply online, so don't actually need forms at all.
You can apply in different counties, just follow the procedure for each.
The councils are very unlikely to write to you, but by registering an interest (ie putting her name down) with the school they are then likely to ensure you get the forms.
You could look at a pre-school for her now, she might enjoy is. My ds2 is a few months younger (3 in a week) and has just started pre-school a couple of mornings a week and is really enjoying it. Or look at it from Sep 2009. Or don't send her at all. Depends on your circumstances and your child.