[Jach]

As another beginner (still <50 19x19 games, so take with salt) I really appreciated the style and content in Janice Kim's Learn to Play Go series' first book. (Partway through the second.) Sensei's Library online is often a good intro to some things too. For manual scoring, the important thing I think is to have a mostly completed board, at the very least borders have been all established so no outside invasion points from e.g. the edges, then if you want you can pretty easily re-arrange stones within boundaries into quads for easier counting and use either area or territory scoring. I like territory scoring since there's less to count: add in the captured/dead opponent's stones to their territory, count all the empty spots remaining. In most games with my coworker though, I use this app to score: https://play.google.com/store/apps/details?id=com.jimrandomh... (Must load pic from gallery.) Occasionally I'll compare its output to my own scoring or even take its sgf and run it through gnugo's scorer, the winner outcomes have always been the same on completed boards even if the exact numbers have differed...

If your kid likes anime, Hikaru No Go is great.