I've never done a full length book translation before, but it's something I'd really like to do. I figure that the pay would actually work out lower, but the schedule would be much more manageable. My longest ever single job was about 3 weeks. My jobs consist of about 50% minimum charge certificates and stuff, and the rest is shorter stuff. I find they tend to be about 1-4 pages.
I wonder if it's better to focus more on the shorter jobs, or to try and get hold of more longer term jobs.
In an ideal world, I think 10 minimum charge jobs per week, with one longer job or so per month would be perfect!