all namespaces, classes, public members (methods and properties), constants have PascalCaseNames : Namespace.Class.PublicProperty.Method()
all fields, parameters and variables have cameCaseNames: _field = variable = parameter
all fields (which are always private) start with underscore: _privateField;
method names are verb oriented: DoActionOnData(), ShowDialog()
give descriptive names, no abbreviations: columnIndex instead of i, etc. only exception are simple loops.
unit test names follow Method_InputParameters_ReturnedValueOrExpectedActions naming format: Add_TwoAndTwo_ReturnsFour()
place each scope operator ({}) on a new line
explicitly declare accessors: public var _field; instead of ~~var field~~
when in doubt follow the same convention as .NET coding guideline and C# Coding Standards.

Declaration

all fields are either private are protected. all fields to be accessed from the outside are wrapped in a public property.
no internal declarations (they're generally useless), unless there's a really good argument to make some class / member internal

Database conventions

each table has AutoID column with automatically incrementing int primary key

Change log in SVN log - If you add new methods to public API for consumption, add them to the commit description. Other people can pick it up. Use SVN log to document new examples, etc.
Method documentation - What method does, takes, returns, remarks, exception thrown are documented at method declaration with XML comments. Resharper can show all this using Quick Documentation keyboard shortcut (Ctrl+Shift+F1 for VS Scheme and Ctrl+Q for older Resharper 2 Scheme)
Examples - Examples of how to use method can be added either to the method docs. A separate example can be added to the test project, to a file ending with "...Examples.cs" Probably both.