It is very daunting, it took me the longest time to catch on. Part of the trick is to try not to look at the whole dog, or you'll be overwhelmed!
I assume you are talking about true hand plucking, not using a stripping knife?
You won't get it all done in one go--too hard on you and the dog! I would do mine while sitting on the sofa in the evening, a section at a time. I find the stuff over their hips and down the sides of their legs seems to come out the easiest, so that would be a good place to start to build your confidence and technique.
I pick up a tuft of hair in my left hand, just enough to fit between my thumb and forefinger, and pluck with my right.(or other way around if you're a lefty) Then pick up the tuft next to it and so on. When you lft the hair that way, then the undercoat will naturally be what is exposed for plucking. Try to visualise a grid pattern on the coat and pluck each section of the grid. If it's fuzzy and "dead" looking just grab the hair, just like above, a little bit between thumb and forefinger and pluck--in the direction the hair is growing--at the fuzzy part
So hard to explain in writing...Hope this little bit helps!