Maybe you can find something good here:
http://msdn2.microsoft.com/en-us/office/aa905455.aspx
http://msdn2.microsoft.com/en-us/library/ms268893(VS.80).aspx

chanmm

About accessing local and shared folders, I just had some questions
about this in another forum and I posted some of my code for anyone
else who asked.  Note the Outlook-specific forums will be helpful for
your project.
http://tinyurl.com/y9zkss

Regarding using Outlook in a multi-user, multi-threaded environment,
this is highly discouraged.  See this well known knowledge base
article on the topic:
http://support.microsoft.com/kb/257757/en-us
That said, there are ways to do this, maybe asynchronously from the
user session.  (Get the request from the user, store it in a database.
Then have a separate process check the db for data that needs to be
uploaded to Outlook, and process each transaction in a single thread.)

Also look into Outlook Redemption (see Dmitry's link in the thread
link above), which will really help with the project you describe.

About ASP.NET to Outlook Appointments, I just wrote and delivered this
to one of my clients - it's very cool when it finally works.  :)

Hope that helps.