There are videos available. I bought one from a YT member and I have noticed the same one for sale on ebay. I passed mine on to my DIL.
As far as supplies, if yo are going to buy clippers, I would suggest going to Petedge.com. They have wholesale prices and clippers will put you over the amount so you won't have to pay a surcharged. Both Oster and Andis are often recommended. You just have to look through them and see which features you want or how much you want to spend. If you search clippers on here, you will get several model recommendations. Oster A5 Single speed is often recommended as well as the andis AGC 2 speed. I had those two written in my notes as prospective clippers if I ever want to try the whole grooming.
I use a little Wahl Peanut trimmer. It is supposed to be just for trimming, but that is all I do. I let the groomer do the major grooming, and I trim a time or two in between. Saves some money and I have the trimmer for those quick little fix-ups when you want them looking extra nice.
Besides the clippers, you will want a nice pair of sharp scissors. I like to use a pair with rounded ends when I cut near the face. I also have a pointed end pair and a forceps I use to twist hair from the ears. A good stainless steel comb helps in the grooming too. They have some nice ones on Petedge, but they are expensive. I bought my forceps and rounded end scissors off ebay. I did get a good pair of pointed end scissors and they are really nice to have!
I bought a small pet blow dryer from Petsmart (I think Petedge has it too for less). It has a stand so I can use both hands for brushing and holding on to the pup. Much easier than when I was using my own dryer.
Petedge.com also sells a small but nice, grooming table that turns for $39.95. I have not got that yet, but have been tempted many times. I know it would make life easier as mine tend to go into stiff mode when I am grooming. So, turning them is near impossible.
If you start a thread "Grooming Video Wanted" in the Yorkie Products Wanted folder, I'll bet someone has one sitting around not being used they would give you a deal on. I watched mine a couple of times, tried it a couple of times and decided it was not for me.