t's easy, I promise. When you want to add a new ball of the same yarn, the best thing to do tie the two balls together with a surgeon's knot, then continue knitting & finish off the ends later. This was a little different, since I wanted the knot to be at the end of a row so it would look like the yarn magically changed from blue to brown. Here's what I did, though I understand there's a bunch of ways to do it:
1. Knit to the end of a row.
2. Make a slipknot with the black yarn and slip the loose white end
of the new ball through it.
3. Push the black knot all the way up so it is snug against the first
stitch on your needle. Tighten it so that it ain't moving.
4. Now just start knitting with the black yarn & ignore the two tails.
When it comes time, just finish them off in the appropriate color.
I hope this helps! Let me know if it doesn't, I'll take pictures of the whole process. Thanks for the compliments on my scarf too!!