David St. Lawrence has an excellent blog where he often posts about careers, small business, and becoming an entrepreneur. In his post The ideal job, he defines the ideal job as follows:
Definition: The ideal jobs are those that prepare you for long-term job security as your own boss.
[microISV]
Some further points from this same post:
The only real security is competence. (and a willingness to embrace change)
Take jobs that make you more competent in ways that will provide
long term opportunities for you. A low paying job in a brand new field
is far more valuable to you than a high paying job maintaining legacy
hardware or software.