Software for diagrams and schematics?

Fritzing is an online service that makes very nice-looking pictures of breadboards. Don't use it. It doesn't have the exact components that you have and a picture of a breadboard is a bad way to draw a schematic.

Don't use Fritzing.

I use Eagle, because I make a lot of circuit boards. The schematics it produces look very good. The free version of Eagle will last you a long time and upgrading to the paid version is not expensive for a hobbyist.

Even Microsoft Visio makes pretty good schematics.