I've had something of an unusual career path, and I've found out first-hand that a lot of companies don't like people with weak resumes / references, and it's hard to build these up (especially references).

I always try to convince companies I'm interviewing with to do a "try-before-you-buy". Of course, it's a lot easier to do the trial week as an employee if you're starting out from a position of being unemployed, rather than taking vacation to do this.