Hi! Welcome!
I, too, just adopted a little Yorkiepoo myself!
So I am getting used to it all, just like you!
He is so so cute! I love his eyes!
Now, I know you asked for recommendations for grooming. I don't have any specific sites, but I do recommend using YouTube! I use YouTube for EVERYTHING! I have learned how to cut my own hair, grill a steak, put extensions in my hair, do makeup, bake a cheesecake and so so so much more! Lol! So my point is, I am almost positive that if you search YouTube you can find a grooming video! And the best part is, they are free! So just go to YouTube and do a simple search in the search bar.
Good luck! And remember, they don't need all the froo froo, frilly, expensive stuff to have a good life -- he is already having a great live because YOU rescued him and brought him into a great home! All the love, care and attention means so so much more than bows, fancy clothes and whatnot! Love and a good home is all he needs and it looks like he has that with you!