How to add new tiles to a current tileset // HGSS or DPPT hero/heroine sprites

How do I add new tiles to a current tileset without changing move permissions?
Also, does anyone know a good place to download protagonist sprites already spaced out with all of the running and offeset sprites?
Tx.

1) One question for topic;
2) You have to open your image in Photoshop, or Gimp, and resize the canvas; then add your tiles and save the image;
3) spriters-resource.com