Starting a new ball of yarn?

I need a better explanation of how to start a new ball or yarn
I have read you can make a knot after 2-3 stitches or gradually adding the second ball
Is it best to do at the beginning of the row?

I prefer to start it a few stitches from the edge unless the edge will be seamed or a border added. I very rarely use knots preferring to weave the ends in. To start I just leave 4-5 inch tail and just start knitting with the new yarn.

Are you talking about when you run out of yarn on one skein and need to start the next one? I usually just leave a nice tail of the old skein and start knitting with the new one leaving another tail. When I’m all done I work in the tails so as to close the looseness and make it look like the rest of the work. Some folks like to change at the edge, personally I don’t. I do it if I’m out of yarn right there but if not I knit on until I am and change wherever I am. There are lots of other methods for switching to a new skein Russian join, braided join, felted join (works for wool) and other ideas but I still just do it the way I described. Look up some of the other methods and try different things and see what works best for you.

When knitting I use this join exclusively… there is also a video there showing how to change colors. Hope this helps you. It just takes a few minutes to do… and it is almost invisible within the project (after you knit a few rows you can hardly find it), and NO ends to weave in, which saves you time in the long run. Also, you never end up with a bulky area within your project.