create a blank disk image file with disk utility by selecting file-->new-->new blank disk image. I would encrypt it and put a password on it.
Save this to wherever you want to keep your files and mount it. Then open it up in the finder and with a separate finder window, copy and paste (first, you can remove them later) the files/folders you want into the mounted disk image file. There now should be two copies of the files, one in the disk image, and one in the original location.
Unmount and remount the disk and make sure the files are in there. After you have verified the files are in the disk image, you can move the original files into the trash and empty it. This will remove them and you will not be able to find them when you search in finder.
This is just a good method for keeping any sensitive files safe by password protecting them.