lindseyr702, there may come a time when the internet becomes a one-stop resource for any plating needs. That time has not yet come.
Lots of information is hidden away in the specialist literature, and much of that is expensive to acquire. Over time, more and more of it will get digitized, but even then, the sheer amount of it is overwhelming.
If you don't have
Stanley Gibbons Great Britain Specialised Stamp Catalogue Volume 1: Queen Victoria, pick up a copy of that for starters. They are not hard to find in good used condition. You can build from there.
It is neat that you want to dive right in to plating, but if you're not careful, you'll be spending all your money on literature and eyeglasses.

(That's not a wink...Smiley is squinting...he plates Penny Reds.)

(That one was a wink.)