MongoDB notes both new and old are offered here.

1. http://twitpic.com/6ix7xr has an example of using Mongo/C#/10gen
2. http://www.10gen.com/ is what one would typically use to interface with Mongo from ASP.NET
3. https://github.com/BancVue/MongoLinqTranslator is BancVue's LINQwithMONGO tool. Ask questions of: peterson.joshua.k@gmail.com
4. MongoDB is a document database like Apache CouchDB or RavenDB.
5. Mongo and Couch use JSON, but Mongo uses binary JSON.
6. The database holds collections. Collections hold documents. Documents hold fields. Fields hold key value pairs.
7. XML is "bigger" than JSON as deserialization is slower, heavier, and fincky with XML.
8. There is a not free version of Mongo that has better security.
9. MongoVUE is a good WYSIWYG tool to browsing Mogno records.
10. 10Gen made Mongo.