The Internet Guide to Funding College and Section 529 College Savings Plans. Savingforcollege.com
is a great website for researching 529 plans.
And yes, you can open a 529 plan prior to birth, but you will need to designate someone else as the beneficiary and then change the beneficiary once child is born.
As a PA resident, any money you put into a 529 plan is deductible on your PA state tax return, not to exceed the federal gift exclusion and not to exceed your reported PA taxable income. Each spouse is treated as a separate person regarding these limits. Doesn't matter what state sponsors the plan.
I live in PA but used the Utah plan for last 14 years but recently transferred the funds to the Colorado Stable Value 529 plan as one is currently in college, the other boy is a year away.