I can't remember which breeder has the in-depth lesson on bathing Silkies....
The type of shampoo depends on the color bird. Since I don't raise white Silkies, I use a no-tears flea formula dog shampoo. Wet down the bird with lukewarm water; NEVER get water on their nostrils, they'll drown. Lather with shampoo; scrub everywhere while the bird stands in the water. I bathe mine in the bathroom sink. Rinse thoroughly~~then rinse again. Then I sit the bird in my husbands sink, lined with a towel, and blow dry on the low setting. The drying part is usually when my bird goes to sleep~~they love it.
Forgot to add that I kind of hold the bird upside down to wash their crest; it's the only way I can do it without the risk of drowning them.
After bathing, I clip their toenails, clip their beak (if it needs it), check ears for any kind of gunk.
It's not difficult and most birds enjoy it.
Good luck