Since the assets in a 529 are held under the SS# of the person gifting the money, they have little effect on financial aid.
The best site for info is
http://www.savingforcollege.com/
Choose the state with the best plan and make sure that you tranfer it to your current state prior to a need for the money, if there is a tax advantage for being in your own state's plan. Because if your state has tax advantages but the plan sucks then don't invest there. Plans can be transfered, all info can be found on the site above.
Good luck