Topic: What personal information might be on my 3DS?

I plan to sell my 3DS as I am getting the Zelda 3DS XL bundle, but I don't want any personal info changing hands. I also don't want to remove the downloaded games I have as they are a selling point (Mario Kart 7, Animal Crossing).

Anything I should remove and how?

Umm... only thing that might be on there is credit card information if you chose to save it on the eShop, and also possibly a linked Club Nintendo account. That's it, though, I'm pretty sure.

If you have used the internet browser, wipe all data there, just clear history and cookies I think.

Apart from that, just delete the credit card info stored in the eShop (if there is any) and unlink your Club Nintendo account if you have one.