Creating a PostgreSQL client application is easy with the tools provided by Visual Studio, but before you start, there's one step that you'll need to follow every time you create a new Npgsql-enabled VB project.
When you create a new VB project, Visual Studio automatically links in a number of commonly used .NET framework components (such as System, System.Data, and System.Windows.Forms). If you're going to add Npgsql components to a VB project, you must define a "reference" to the Npgsql assembly. If you're not used to .NET terminology, think of an assembly as an object library, and the process of adding a reference as analogous to adding that library to the link command line.
To create a new VB project, open the File menu and choose New, then Project. When the New Project dialog appears, select Visual Basic Projects (in the box labeled Project Types), then click Windows Application (in the box labeled Templates).
To add an Npgsql reference to your project, open the Project menu and click Add Reference. When the Add Reference dialog appears, click Browse and open the Npgqsql.dll file (you'll find it in the DesktopNpgsqlinms directory if you've followed my recommendation). Click the Ok button to close the Add Reference dialog.
Part I: General PostgreSQL Use
Introduction to PostgreSQL and SQL
Working with Data in PostgreSQL
PostgreSQL SQL Syntax and Use
Part II: Programming with PostgreSQL
Introduction to PostgreSQL Programming
The PostgreSQL C APIlibpq
A Simpler C APIlibpgeasy
The New PostgreSQL C++ APIlibpqxx
Embedding SQL Commands in C Programsecpg
Using PostgreSQL from an ODBC Client Application
Using PostgreSQL from a Java Client Application
Using PostgreSQL with Perl
Using PostgreSQL with PHP
Using PostgreSQL with Tcl and Tcl/Tk
Using PostgreSQL with Python
Npgsql: The .NET Data Provider
Other Useful Programming Tools
Part III: PostgreSQL Administration
Introduction to PostgreSQL Administration
Internationalization and Localization
Replicating PostgreSQL Data with Slony