Whats the typography rule for numbers?

Question: Whats the typography rule for numbers!?

I read somewhere that you should type 1 to 9 as One, Two Three, Four etc!.!.!.when typesetting!. Any numbers after 9 should be in it's digit form, for example, 10 should be 10!.

I hope i'm making sense!. My query is, I think I might have gotten this rule messed up!.

Anyone know, in detail, what the golden rules are for when you are creating nice typesetting!?

Cheers!.!.!. :)Www@QuestionHome@Com

Best Answer - Chosen by Asker:

Here's a good collection of rules:

http://www!.grammarbook!.com/numbers/numbe!.!.!.

I usually write out numbers up to, and including, twelve, and always at the beginning of a sentence!. I write it as digits, of course, if I'm writing a list!.Www@QuestionHome@Com