If you have a GPS system, enter the Disneyland address: 1313 S. Harbor Boulevard, Anaheim, CA. It will take you to the front gate, and you can follow signs from there to the parking areas.
If you're traveling across Los Angeles to get there, you'll have a ton of options for routes. Check traffic reports on the radio or using your smart phone before you set out to figure out which route is least congested.
Once you get to Disneyland, parking is very efficient. Just follow signs and friendly people directing you and you can't go wrong. If anyone in your party has mobility problems, just tell the parking attendant as you go in. They have special parking places and vans to take you to the entrance.