I have one of these plans for my 3 1/2 year old son. I opened it up when he was 1. I'm expecting another baby in early December and plan to open up his account right away. I used a direct buy 529 plan which all states offer. I just went directly to the plan website and opened online rather than purchasing from a finance guy since all states offer plans that you can just sign up for directly on your own.
From the research I did when I opened my son's account, I found that the fees charged by 529 plans sold by brokers were substantially higher than those for the direct sold plans. The brokers could take anywhere from 1-6% of the total money you are investing for sales charges on top of the expense ratios for the funds themselves. I've never read anything that shows that funds sold by financial planners outperform the ones you can get yourselves since you always have to pay extra fees to the planner so you are always having return reduced by the percentage they take. You can go to the following website to do research on the funds and get additional information on the various 529 plans offered by all states: http://www.savingforcollege.com/
At the time I started a 529 plan for my son, the PA plan was not very good and had relatively high fees. I signed on for the Nevada 529 plan which is managed by Vanguard and has exceptionally low fees and has age based funds available to make investing easier. At the time I signed up, Pennsylvania also started permitting deduction for 529 contributions up to $12,000 for plans in any state. Pennsylvania has since changed to have Vanguard managing their 529 plan. The expense ratios are a little bit higher than that of the Nevada plan, but the initial investment is cheaper ($25 for PA versus $3000 NV, although you can open the NV for less, you'll just have to pay a surcharge until the balance reaches $3000). Also, Vanguard has some good tools on their website to allow you to compare plans from the different states and their costs: https://personal.vanguard.com/us/whatweoffer/college?Link...
I use funds that are auto-adjusting by age to simplify things rather than having to monitor a lot of different funds.