Take the A1 Autoroute du Nord (Paris - Lille motorway) northwards from Paris, take the Chantilly exit, southwards from Lille, take the Survilliers exit. Alternatively, drivers can take the RN 16 or RN 17 trunk roads. Chantilly is usually less than one hour's drive from Paris (depending on traffic).
To access the château from Chantilly station, you can take a taxi from the station (€6), or catch the Cariane bus for Senlis (free in Chantilly).
To walk from from the terminal (at the head of the SNCF lines), get off at the Chantilly stop and walk to the Château from the terminal, around 35 min.
The best way to get to Chantilly is definitely from Gare du Nord although you can take the metro but it's much slower and more crowded.
Once you arrive go out of the station and turn left. Walk through the alley which is then straight ahead of you and you will reach the bus station - 1 minute. there you can get the free bus to the gate of the estate, near the stables. Walk throught the big arch gates and its 5-7 mins walk to the entrance lodges where you buy your tickets.
Be warned: you won't be able to get a taxi between 12.00 + 14.00. It's lunch time!
Château de Chantilly is the second museum in France after Le Louvre museum for old paintings from the 15th to the 19th century: Indeed, no other French museum presents three Raphael, three Fra Angelico, one Enguerrand Quarton, several Clouet, four Watteau, four Greuze, five Nicolas Poussin, five Ingres, three Delacroix, etc., all of great quality. Must see the medieval illuminated book of hours by John Duc de Berry, famous for it's illuminations and natural art work. You can see a replica of the original 'Les Tres Riches Heures' and look through the whole book via their electronic copy.