Since the underground library parking is no longer free you need to know about the surface parking.
There are two surface lots across Park Blvd from the library that are reasonably priced. The closest lot is immediately across Park at the 11th St. stoplight. This lot is $5 all day and uses a dashboard ticket to show you have paid.. You enter the lot from Park Blvd. The ticket vending machine is right inside the lot and takes cash or credit cards. It does not give change.
There is a $3 per day parking lot across the trolley tracks from the above mentioned lot. The ticket vending machine is in the extreme southwest corner of the lot. This is the corner that is closest to the 12th and Imperial Transit Station. I'd recommend entering this lot from Imperial Ave westbound so you can drive right to the ticket vending machine. Get your parking stub and drive through the lot be close to the library. There is a shrubbery island that divides the parking lot and it looks like it divides the lot to prevent full access to the library part of the lot. However there are two fire lanes through the shrubbery that you can drive through. You have to look for them but they are accessible.
There are no in and out privileges on either lot. Both lots cost $15 to $20 on baseball game days.
There is a multi-story parking structure at the northwest corner of the library but I haven't priced it yet.
Bus and trolley are good choices too. All three trolley lines stop at the 12th and Imperial Transit Station. The transit station is only a long block from the library.
Buses 11, 901 and 929 stop at the library.