Fusion CAM question

Seeed Services Fusion PCB/ PCBA Services
2
  1. Open your eagle board design.
  2. Choose File / CAM Processor.
  3. Load fusion file by File / Open / Job… then find and open the file
  4. Run the CAM processor by clicking Process Job.

Now the generated files should be in the same directory as your eagle board file.
You could also submit the eagle board file directly to fusion without generating gerbers (according to http://www.seeedstudio.com/depot/fusion-pcb-2-layer-5cm5cm-max-p-513.html?cPath=64_12 “We accept Eagle, Protel, Allegro, and preferably Gerber files.”).