Capacitive sensor, what do i need?

Hello, i want to create 4 touch sensors I will hide behind pieces of plexiglass. Where should I start from?
I saw the capsense library, but I didn't tried it yet.
I also saw there are several chips for this kind of activities.

Thank you very much.

What function do you request capacitive sensor for? for pressure measurement? or the other?

I need user to touch it in order to activate it.
I imagine something like Samsung televisors or phones, where you touch the plastic/plexiglass in order to give commands.