Here is a short explanation, hope this helps.
To count knit rows, find the center of the knit " V" right above the cast-on row. Follow the column of knit stitches by counting the centers of each knit stitch. ( the center of each v )
I have a book that says NOT to count the cast-on row unless the pattern specifically says to.
The last row is the one just below the needle - the stitches on the needle have yet to be knitted.
Have you ever looked at that book, Knit Fix by Lisa Kartus? It is great and gives a picture on counting rows.
Hope this helps.