I've just been looking into this so the info is quite fresh in my mind!!!
It really depends when you think she'll be ready to start pre-school and when you can get a place for her. Like Sarah said, most start after their third birthday, although some pre-schools will take children in the term before their third birthday and with yours being a November birthday, you might want to think about her starting in the September before she's three, if the school will take her and if you think she's ready.
It also depends on where you live how long the waiting lists for pre-schools in your area are, particularly if you want to choose the pre-school she goes to rather than just seeing if the local one to you has places.
I live in the outskirts of London, so our situation is slightly different as pre-schools where I live are just so totally oversubscribed - My DD is 11 months and I've had to put her on the waiting list for pre-schools in my area now!!!!! Ridiculous, isn't it!!!! Don't let that panic you, though, as London is generally a daft place to live when it comes to your child's education.
The government funds a certain amount of pre-school (I think they fund 4 sessions a week???) and this funding kicks in the term after you turn 3. So, if she's a november birthday, she would get government funding from the january after she turns three, if you wanted her to start then. Hope I haven't confused you!!!!
Loocy xx
[