Jacques Greyling, Operations Director at Rackspace (www.rackspace.com), says:

Simplify what you offer.
Having too many options or features available might not always be the best in the long run. Customization= Complexity, and it will put your business in a spiral that always tries to cater to everyone rather than focusing on what will work for 80% of the business. The other 20% could be outsourced.

Simplify your vendor selection process.
Ensure that you have a well thought out, simple vendor evaluation process. Keep it focused on your business requirements, be careful of scope creep. If you feel pressure to sign, don’t. You always have the option to sign later.

Have a clear Statement of Works or Service Level Agreement
Ensure that you have a clear Statement of Works or Service Level Agreement set out from the start if you plan to outsource any functions. This will avoid confusion of who need to deliver what piece of the function and it will allow your employees to have clear vision of how they need to work with this new partner.