Here’s the breadboard view in Fritzing. Whenever I need “holes” to solder random components into I just use screw terminals. I’m sure there’s another/better way, but I’ve not found it yet, so I keep doing it this way.
Once the breadboard view is done, I go to the PCB view and move things around, make all the connections, and then export the files in Gerber format. Once you have a folder of Gerber files, you can ZIP it up and then upload to OSH Park for fabrication. (I covered this process in a previous post.)
I did find this Mac OS X application called MCN Gerber Viewer which allows you to view Gerber files. You can view the different “layers” and turn them on and off to check your board before fabrication. OSH Park shows you what your board will look like when you upload it, so you can easily check for issues, but MCN Gerber Viewer is still handy to have around to check files before you upload them.