Update- Solidoodle officially supports Repetier and has a pre-configured download with Slic3r profiles available here.
Here is a long, but thorough video walk through of setting up Repetier Host. Repetier is a complete printing software solution, from loading and orienting STLs to slicing in Slic3r or Skeinforge, to controlling the printer and running the print. It also has a great 3D visualization of the gcode itself so you can get a preview of how the model will be drawn out.
Please excuse my pronunciation of Repetier, I had assumed it was a French word (as did Google Translate) but it is in fact German.
The current Marlin firmware, configured for Solidoodle – mlaws/solidoodle2-marlin
The download page for Repetier Host – Downloads · repetier/Repetier-Host
Repetier for Mac – https://github.com/repetier/Repetier-Host-Mac/downloads
Here is the config for Slic3r. There is a preset in the Printer Settings section which has the start code for Repetier- Slic3r Config for Solidoodle
The start gcode-
The X Home position on the Solidoodle is actually about 9mm past the edge of the printbed, so if you set the size to 150mm wide, the center will be off by 9mm to the right, anything placed in the rightmost 9mm will fall off, and the left 9mm will go unused. Setting the printer width to 159 will bring that left side back, but it will also allow STLs to get placed into that open space on the right.
Repetier has a feature called Dump Area, which is a section that can be defined as off limits for printing. Rather than draw a skirt, you can have the nozzle go to this area before a print and extrude some plastic into space, to fill it up and replace what might have oozed out. We can use Dump Area to account for that open space between X Home and the edge of the bed-