Here is a list of videos I recommend to help you get start with knitting:
Long Tail Cast On
Very Pink Knits. I love her videos, I usually start with her series when learning something, but I like watching multiple videos to find the subtleties that will work for me. This video is great for long tail cast on with a slip knot. I think it's a wonderful beginner way to learn how to do long tail cast on.
Long Tail Cast On: https://www.youtube.com/watch?v=sN9cNEozOLc
Another version with the slip knot start: Long Tail Cast On
This is closest to the way I do it. I like how slow she is in showing how to do a long-tail cast on. Long Tail Cast On
Learning how to knit - Continental Style
Continental and English style knitting are two methods of how you hold the yarn while knitting. I learned English and was encouraged to switch to Continental because my hands would hurt with the English style. I'm very glad I made the switch. Continental is overall more efficient (i.e. faster) because you move your hands less. You can get very fast with the English style, but your hands still move a wee bit more. However, as is pointed out in the last video, it's good to know both styles of knitting to help when you have repetitive motion stress/injury. Being able to switch it up gives your hands and arms a rest.
This is one is good with beginner continental.... but how she pulls the stitch through is good for beginner but very inefficient in the long run. However, I like how she teaches this because it's how I've noticed beginners tend to work when learning Continental.
When you get comfortable with the beginner, here is the version that helps you refine your continental knitting. This is the video I used to help me when I switched from English to Continental.