Simple. Whatever it takes without being uncomfortable about it.
Things I will gladly do:
- phone interview with as many people as you like
- physical interview until I think you have enough information to decide
- share any of my work face to face
- on-line third party evaluation (code test, personality, etc.)
- review any of your system with you
- code for you in person
- sharing on-line information (including all hn posts)
- doing up to 8 hours of free sample work
- provide a referral if they are a better fit
Things I strongly push:
- in depth discussion about the employer's situation
- reverse interviewing employees with similar jobs
Things I will gladly do, but only “after” a job offer:
- provide references
- drug test
- credit check
Things I will never do:
- have a generic resume (every one is uniquely targeted)
- post any resume on-line
- pay a fee
- physical interview with a head-hunter
- provide anyone else's proprietary information
- "bad mouth" anyone else