>I looking for info and sample code etc... on how to use VFP in a .NET environement.

Here are some articles:
http://www.west-wind.com/presentations/VfpDotNetInterop/vfpDotNetInterop.htm
http://msdn.microsoft.com/library/?url=/library/en-us/dnfoxgen7/html/usingaspnetwithvfp7.asp
http://www.levelextreme.com/Magazine/July2002/Page16.asp
http://www.levelextreme.com/Magazine/April2002/Page18.asp
http://www.levelextreme.com/Magazine/April2002/Page14.asp

>Also what is the best complementry language (ASP.NET, VB.NET, C# ,...) I should learn to deploy my VFP apps on a .NET environement.

I think it is mostly personal preference whether your choose C# or VB.NET. ASP.NET allows you to use C#, VB.NET, Cobol.NET or any of the other .NET languages.

>Or should I simply drop VFP and move onto VS.NET

That is up to you, but I think VFP and .NET play well together. I am working on a project that replaces my VFP app UI with ASP.NET then calls my VFP biz tier, that is compiled into COM components. I'm impressed with the speed and relative ease of doing this. Not that there haven't been challenges. The challenges stem mostly from learning the VS.NET IDE, the .NET framework and C#.

To learn .NET:

.NET for VFP developers book
http://www.hentzenwerke.com/catalogavailability/netvfp.htm

Visual FoxPro Toolkit for .NET
http://www.gotdotnet.com/team/vfp/