Intarsia/Stranding?

I want to knit a blanket with a few different colors . How do I know if I should knit it intarsia or by stranding? Also, How do I begin that? I have watched the video but I dont know where to add my new color so I can start intarsia knitting! This is all really confusing!Please help
SIS

Intarsia has blocks of color in one spot, sometimes forming a picture or a letter. Stranding is carrying colors across a row; knitting a few stitches with the main color, a few with the contrast color or two. You might be thinking of striping where you knit 1 to 10 rows in different colors. So it depends what you have in mind for your colored blanket as to how you do this because each is a completely different technique.

If you’ve looked at the KH videos here’s some more help if you need to see two different perspectives.
http://www.community.knitpicks.com/notes

To start a new color you just start knitting with it just like any other time you do it. If it leaves a gap (probably will) you use the tail to fix that later when you weave it in.

Which one you use depends on the design you choose.

Thanks for sending me to Knitpicks . I now understand that I need to wrap in to cange colors mid row!