Anyone ever been?
my dad said he's always wanted to go, so for his 70th birthday I thought it would be a great present. I'm not worried about flights, I would just like to know how the experience is there, and if anyone has insight into good hotels close by
Book hotel ASAP. Everything gets booked up way in advance. We ended up having to stay in some sort of La Quinta or something like that because that was all we could find. Try to find something with shuttle service. Make sure you go to the Kentucky Oaks the day before. It is fun, too. Just buy some infield tickets for lime $20. It is a throw down. You will love the Derby. You will be shocked how rowdy it is. Tons of smoking hot chicks, all dolled up, getting hammered. 
Do it! Lived in Louisville my whole life. I've been to Super Bowls and most major sporting events.. they do not compare. Get here on Thursday, go to Oaks Friday and Derby Saturday. You cannot beat the feeling of "My Old Kentucky Home" being sang as the horses walk out for the Run for the Roses!! 
usually head down the night before, get hammered, spend a bunch of money at Deja Vu, sleep in the bed of my truck, then stumble into the infield for more drinking and a major sunburn
Sounds awesome! Thanks for the advice. I'm booking the hotel within the next week. Will that be enough time?
Just realize if you are in the infield you are not there for the race but for the atmosphere and party.
Unless things have changed since the times I went you won't see many horses running.
Infield for the oaks on Friday (order a fleur-de-lis).
Grand stands for the derby. Try to get somewhere on the backstretch (order a mint julip).
You and your dad will love it.