I've breed Cherry Barbs before and in a normal display tank you probably won't see the eggs from any Barb species due to size and color alone. They are very small and transparent, not to mention probably becoming a meal.
This Thursday, however, I will be attempting to breed Tiger Barbs which I have been conditioning for 2 weeks now. What I do is put a pair in a 5.5 gallon tank with an egg trap (egg crate & mesh material) & java moss. I know the eggs have been laid when I shine a flashlight on the bottom of the tank. I use the same test for Tetra eggs.
I'll let you know how it goes.