It's hard for us to suggest any one particular style - the way she wears her hair depends on the style of dress she is wearing, her face shape, etc.
Here's some links I found with Step-by-Step instructions...
http://www.hairboutique.com/tips/tip3510.htm http://www.hairboutique.com/tips/tip1116.htm
This one looks really easy to do - but the results look super complicated!
http://www.hairboutique.com/tips/tip1014.htm
This site has some instructions too...
http://styles101.homestead.com/updos101.html
Hope this helps... Post pictures when you do the 'do!