How do I connect two solar panels in series?
I connected the negative on panel A with positive on panel B


This is a good start


  and positive on panel A with negative on panel B


But what is with this?



This is how it should be done.

And what is with the diodes? You should only use a diode when having a dual supply (panel and other supply) and you want to prevent current from the supply going into the solar panel.