I personally think the concept of apprenticeship is lacking in the technology industry and we loose out on what other older professions have with clearer career paths because of their established practices of guiding people though their careers. That said I've seen it abused too so there always needs to be balance in these things.
I personally coach about five people (for free) in my current company and they come from all areas of the org not just my group. I was very lucky in the early days to have several great mentors in my life who helped me and I feel it's my job to pay that back now in the latter years of my career.
Books are wonderful but nothing beats interacting with successful people.