New sales process

I am doing a review of how conuslting firms, particularly mid-sized and
large ones, approach new sales (i.e.: securing contracts/work from new
clients)
I am particularly interested in:
- The organizational structure used (e.g.: the ratio of sales/business
development executives to consultants, sales vs. research/support roles)
- The approach taken (e.g.: the role of pre-work, use of non-billalbe time,
etc.)

Your help would be most appreciated.

Saar