I've read and enjoyed the Thursday Next series a lot.
I hadn't read Jane Eyre but I could understand and enjoy the story without any problem.
But it sure helps to have at least a bit of knowledge in english lit classics.
My wife and I have recommended and offered these books many times to friends and family, and each time it was a success.
As a side note, you can find another conversation on Japser Fforde here :
https://www.mobileread.com/forums/showthread.php?t=13273