Networks

Hi,
I have been working for approx 2 years with Sharepoint, mainly administering the servers (WSS2, 3, MOSS2007, 1500 users, ISA external access, multiple AD) and also developing Custom sites (adding html, javascript, css .. that's all)
I now want to develop a bit more and provide business applications where Sharepoint designer limitations are. I used to program in Lotus Notes and have an IT degree so I figure I should be OK in OO Programming (still).

Question is : we talk a lot about .NET, .Net 2.0, 3.5 .. etc..
but also about ASP.NET, ADO.net ..
all this is a bit confusing for me, where / what would be the best path to start with ?

I saw a course for "SharePoint 2007 Training : MOSS 2007 & WSS 3.0 Application Development Training Course "
http://www.jbinternational.co.uk/sharepoint-2007-training-sharepoint-application-development.html

but it seems that the prerequisite is "Introduction to ASP.NET 3.5 Training Course UK with LINQ and AJAX "
http://www.jbinternational.co.uk/asp.net-3.5-visual-studio-2008-training-course-uk.html

Shall I go to the latter then ?
I mean : ASP.NET programming in VS2008 is going to help me start creating apps for Sharepoint right ?