First, CONGRATS to your daughter!!
Seondly... from a girl who is planning her wedding (along with a few others..) PLEASE.. for the love of everything good in the world.. remember that it is HER wedding... NOT your's. (Can SOMEONE please call my mother and reminder her of that? She doesn't get it..) Listen to her.. BE FLEXIBLE.
Third - Set a budget, but allow that buget to be slightly fluid. If the Dress of her DREAMS is $1000.. cut back somewhere else.. or let her get it. (Again, someone want to call MY mother?

)
Theknot.com is amazing. So is UltimateWedding.com they both have great resources! (I use both!)
Make a list... either by paper.. or on a program such as MS Excel (excel will help keeping costs and such in tact.)
Finally.. ENJOY THIS TIME! I know you're FULL of emotions.. so is your daughter.. but please remember that this is a JOYOUS occasion!