A carpenter goes through an apprenticeship under an experienced carpenter before he actually cut his first 2×4. A physician goes through a rigorous Residency program before she starts her own practice. A scientist does a fellowship and often a post doctoral fellowship before he goes inventing all by himself. Lawyers do work for a senior before he starts his own law firm or being offered a partnership. IMHO programmers are the only group, who will start right on their job.
Jeremy writes about his experience here
Mentoring Other Developers – Jeremy D. Miller — The Shade Tree Developer: “We constantly gnash our teeth over how our industry just isn’t ‘mature.’ We propose certifications and guilds and brown bags and whatnot. Maybe all we really need to do to start is just help each other out with bare bone basics first. ”
IMHO a green horn should be put into a maintenance project, may be multiple ones, his first year. Sorry for being cruel, but it helps.