Can the friends of MY friends see my facebook posts/wall?

[Paul]

Yes, it will take them to your wall. But if your don't want them to see your posts, updates or any information, that can be done. To hide your profile information, you can edit the viewing option to friends only, you'll find it in your timeline editor. and if you want to hide your posts and update, you have to change there preference to friends only. You can do it either from your account settings, or you can do it with each post manually.