Together with OLE DB and ODBC, ADO is one of the main components of Microsoft's Universal Data Access (UDA) specification, which is designed to provide a consistent way of accessing data regardless of how the data are structured.

ASP Data Access for Beginners 
If you are an ASPiring developer seeking a solid foundation in dynamic Web site creation, then look no further. This article details how to connect to a SQL Server 7.0 database using ActiveX Data Object (ADO) and Open Database Connectivity (ODBC).

A Practical Guide to ADO and OLE DB
Contains a tutorial that will walk you through OLE DB, ADO, Universal Data Access (UDA), and how these pieces all fit together.

ADO Programming
Excellent introductory article on how to program with ADO from Microsoft.

ADO Workshop: Using the Connection Object
Describes how to use the ADO Connection object. This is the first in a series of workshops that explores the individual objects in ADO (ActiveX Data Objects).

Microsoft ADO Web site
Official site for ActiveX Data Objects (ADO). Inlcudes links to articles, technical specifications and marketing materials.

Microsoft OLE DB Web site
Official site for OLE DB. Includes links to articles, technical specifications and marketing materials for ADO, OLE DB, and Microsoft Universal Data Access (UDA).

Microsoft Active Server Pages FAQ
Answers general questions about ActiveX Data Objects (ADO).