What train travel would people recommend to get from Apeldoorn to Lille.

I tried the Dutch Rail website and I didn't have any luck. I would suggest trying the German train website - Die Bahn. It will give you the options for travel. You will probably go from Apeldoorn to Schipol and then from Schipol to Lille via Brussels. There are a couple of different ways and it will vary in price.

I would probably wait until you get there and then check at the train station in Apeldoorn for the best options and make your reservations at that time.

I also moved this post to the Rest of Europe to give it wider exposure to our members.

It'll be a long journey!
Here's what I found:
Apeldoorn / Rotterdam on an InterCity train
Rotterdam / Bruxelles Midi on a different Intercity train
In Bruxelles Midi change to Eurostar destination Lille
Total journey: 5 hours 16 mins.