The best place to start is at MSDN, specifically at the "Office
Development With Visual Studio" section, at
http://msdn.microsoft.com/en-us/office/aa905533.aspx

Read up on VSTO (Visual Studio Tools For Office), and VSTO Second
Edition (SE) if you are developing for Office 2007. As an aside, I
build all my NET-based add-ins for Office using"Add-In Express 2008
For NET" and "Add-In Express 2007 For VSTO", both from
www.add-in-express.com . They're not cheap, but for commmercial
quality NET-based add-ins for Office, they are well worth the expense.

You can build NET-based add-ins for Office in any NET language --
VB.NET, C#, or C++.

Cordially,
Chip Pearson
Microsoft MVP
Excel Product Group
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)


On Mon, 17 Nov 2008 06:51:01 -0800, GM
wrote:

In VS 2008, we have the option of creating Excel addin, workbook and
templates. Is there a document that provides guidance on when to use each of
these methods?

Also, addins are they only available for C and C++?
thanks,

GM