The table below contains references to articles I found while building n:m relations in a .NET 1.1. Datagrid.

Some samples on Data binding
Data Bindinging .NET / C# Forms on Akadia.com A general article about Data Binding.
WinForms Data Binding Lessons Learned by Roy Osherove Decribes using an extra column in the master DataTable for n:m relations.
Tackle Complex Data Binding with Windows Forms 2.0 on CoDe Magazine Decribes redesigned controls in .NET 2.0 that make it easier to keep complex data collections synchronized

See also:

in MSDN Help.