Рекомендую ознакомиться с очень простой ORM
CoolStorage.NET.
Supports SQL Server 2000/2005, MySQL, IBM DB2, SQLite, MS Access
Any existing relational data model can be mapped to CoolStorage objects with minimal effort
All relation types are supported: One-To-One, One-To-Many, Many-To-One and Many-To-Many
Completely typed object model (no type casts required)
Full support for transactions, including .NET 2.0 TransactionScope
Nullable columns can be mapped to .NET 2.0 nullable fields or any other value
Delayed (lazy) loading of data to minimize database access
Powerful and intuitive database-independent object query language
Flexible event framework to intercept any event
Identity (auto-increment) keys are supported for all database types
Support for server and client generated Guid keys
Sessionless data access
Objects can be mapped to different databases, even across object relations
Pageable object collections
Extensive support for retrieving aggregate values on collections (count, sum, average, ...)
Collections implement IBindingList so they can be used by controls (grids) as a data source
Underlying database engine uses optimized and parameterized SQL queries. SQL injection is impossible
Built specifically for .NET 2.0, taking full advantage of generics and nullable variables
Raw SQL and/or stored procedures can be called on the underlying database without the need for a separate database connection
Small footprint (less than 150 KB)
Использую у себя на сайте — жутко понравилась

В профессиональной деятельности использую XPO от Devexpress, должен сказать, что CoolStorage.NET ей неплохой конкурент (да и халявный).