The most common way, if you happen to have a broadband Internet connection with a router, is to make a home network and copy the files over.
But there is nothing wrong also with copying to an external hard disk or USB-stick on your old computer and copy from there to your new one.
Of course, the best way is to just copy them from your backup. If you didn't make a backup, it certainly is time to buy that external hard disk. First to transfer that data to your new PC, and after that to make backups to.
how do i transfer data from old pc running windows 7 to new pc running windows 8.1?