I hope this doesn't sound like a promotional plug but I think that many posters on this forum would be interestd in taking a look at the recently published document on Commissioning and the Community Sector. This focuses on helping third sector (and particular smaller, communuty organisations) understand about how Children's Trust commissioners work.
You can download it here
Other resources on the Commissioning Support Programme website may also be of interest but I don't want to bombard members with links.
If you have any questions then do feel free to email me on email@example.com