Flowcharts / software design

Any tips for a software designer / flowchart thingy?

I'm working on a server, it's getting complicated now and I am struggling drawing out objects, their properties and logic flowcharts on A4 bits of paper. It's just not a strength I have.

Any freeware out there that I can use? - It needs to let me design objects with their properties and then basic flowcharts - preferably with events..

I am really struggling to keep it all in my head!