As with any type of engineering or development it is vital to have a framework that outlines requirements and provides expectations of the way in which something should be built in order to meet best practice; Software (CRM) development is no different. Coding Standards enable us to have consistency and scalability, to reduce risk and provide a clear structure for writing code.
Every developer brings their own style to the code they write and will have probably learnt from different people and places. These things influence what they bring to your organisation and have the potential to create conflicts with the code written by other members of the developer team. Guidelines allow the team to write code in a standardised way that represents your organisation well. It is exactly like having a code of conduct for your workplace.
As a Microsoft Partner, we have found a good starting point to creating standards is in SureStep (Microsoft Project Management Methodology). Otherwise a search on the net using key words such as coding standards, coding guidelines will bring up a number of blogs and resources that will assist you in writing your standards.