lol, I don't use plans for anything I build. Only time I did that was when I was a cabinet maker making custom cabinets over and over again to fit w/in kitchen dimensions. Hell, I didn't use any plans for my shed or pool deck, all from the noggin my friend
What type of wood are your cabinets? What I would do is measure the space that is needed and create a box to fit w/in that space. Next is to figure out the type of backing, either paint the wall or put the same type of wood as the background.
What's next is to figure out if you will be trimming the facade of the plate rack or if you will keep it exposed...
Now you'll need to build the actual plate rack. What I would do is get some wood (depending on your cabinet wood) and cut to the width of your box. You'll need 4 pieces, same length, width and height. You'll also need to figure out the spacing to place the dowels (I'd go with 1/4 to 3/8" dowels) and space them evenly along the width of the piece of wood.
What you can do now is install (nail and glue, or screw from above and below (prior to intalling the box) these pieces of wood (they'll look like jail walls). Normal plates are about 12" wide, you'll want to install the two jail walls about 9-10" apart, centering them w/in the cabinet box.
Its hard to explain in text but hopefully it'll give you some idea. Here's a the box I made that wen't over our microwave. It wasn't very useful as a plate hoder so I made it into a nicknack box...
I did the same routine over the fridge, however I made a wine rack that holds 10 bottles of 750mL wine...
Also,
If you want, get me dimensions, wood type, style and I could build it for you for a nominal price