When I was young my mom gave us money for doing chores, but my personality was that I would rather not do the chores and not get the money, so that didn't work too well. When it came time to think about allowance for my kids, I read all the views about everything, and liked these articles best (from Crown Financial):
http://crown.org/Library/ViewArticle.aspx?ArticleId=404
and this article in two parts...
http://crown.org/Library/ViewArticle.aspx?ArticleId=342
http://crown.org/Library/ViewArticle.aspx?ArticleId=343
We started giving out kids allowance when they were 4 and 6 (they are 6 and 8 now). Here's the method that has worked extremely well for us so far... Each week they get half of their age and it gets divided up into "banks"--10% for giving (we give to our church), 50% for savings (they have to wait until they have saved at least $10 to spend their savings bank), 40% for their spending wallet (which they can use pretty much however they want). I'm sure out allowance method will change as the kids get older and their needs change...
So my 6-year-old currently gets $3 each week--30 cents to her giving (tithe) bank, $1.50 to her savings bank, and $1.20 goes in her wallet. The $1.20 doesn't sould like much, but it's just enough for her to get a pack of gum or something from the dollar aisle, or she could save it and get something bigger the next week. The idea is for the amount to be enough for something small, but too much, so they are encouraged to save.
ANY toy that she wants, she saves for. I don't buy it unless it's for her birthday or Christmas or some super special occasion. So thank heavens! there is no more whining in the store! All I have to do is ask her how much she needs to save to get it, and she looks at the price. At first she would buy anything just to buy something, the money burning a hole in her pocket. But recently she has become more particular about what she REALLY wants to spend money on since it is her money.
From my own experience, we decided not to tie the allowance to chores. We require out children to do their part around the house because they are part of the family and we all work together as a team. They can earn extra money for some specific big jobs, though.
Instead, we've told them that their allowance is our way of teaching them how to make good decisions with money so that when they grow up they will be smart with their money. We talk often about how mom and dad have to make decisions like buying food instead of a new fancy gadget, and we are somewhat open about bills so they are aware that we have to prioritize where the money goes. Last week my daughter got to see how saving $5 at a sale at Target meant we had money to spend on an ice cream treat. It's all about choices...
However you decide to go, I think the important thing is to be very clear with yourself and your child exactly what purpose the allowance has and what you expect her to do with it (or for it). Good luck with it!