Penn State Football Parking Map (.pdf). Full statement, which you should read if you're attending the game, can be found on GoPSUSports.com.
Parking lot capacity will be diminished on the west side of campus. Fans are strongly encouraged to approach the stadium from the east, using Interstate 99 / U.S. Route 322, where parking will be more plentiful.
The affected lots for all stadium traffic are: Yellow lots 9, 12 and the Family-Friendly Lot, as well as the Brown Lot, all of which are located west of Beaver Stadium off Park Avenue. Those in the Brown Lot will be directed to park in the Orange Lot off Park Avenue and should approach the stadium from the east. Those who normally park in Yellow Lot 12 also should approach from the east and will be directed to available Yellow Lot parking. Patrons who have a Family-Friendly Lot parking permit should approach from the west and will be directed to the paved area in front of the Housing and Food Services Building.
Patrons who normally park in reserved spaces on paved lots will not be affected.
Again, full statement (including RV, ADA, and shuttle information) can be found here.