List of Best Practices for C# and SharePoint development

Here are Guidelines for Naming Convention, Design Considerations, Best Practices, and Coding Conventions. They are definitely for C#. Web parts should be written in C# as well , so these conventions can also be applied to them.

C# Guidelines, Naming Conventions, Design Considerations, Best Practices, etc

C# Coding Conventions and Best Practices

Below is some best practices when developing web parts, and any code that uses the SharePoint Object Model. Generally, these do not go into code syntax or anything like that. They do go into issues specific to SharePoint development.

Best Practices: Using Disposable

Best Practices: Common Coding Issues When Using the SharePoint Object Model

Checklist for Creating SharePoint Web Parts

10 Best Practices For Building SharePoint Solutions