I've been asked to create a directory for my intranet to display
products, categories and subcategories.
They want it to look exactly like the Google Directory
(://www.google.com/dirhp) or the Yahoo directory
(http://dir.yahoo.com/)
(three subdirectories below each category -Not In a tree but in
three columns-)
I need to build it using asp.net and sql server I have
already built 3 tables -Product, category and subcategory-
How can I do that? where can I find a tutorial?
Thanks

There are a lot of details to what you are doing to try to cram them
all into a single post, but you are on the right track so far.

You need to first figure out how to query data using ADO.NET.  Here's
your basic tutorial for this:
http://samples.gotdotnet.com/quickstart/aspplus/doc/adoplusoverview.aspx

Many examples on the web will explain how to build your own custom
DataAdapter, custom DataList or other wrapper classes to abstrat your
tables.  Initially you'll want to avoid building anything custom and
just use the built in .NET objects like DataAdpater, DataTable and
DataReader.

So now you've got data.  Now you need to turn it into HTML.  For this,
you will use an ASP.NET control.  There's probably already a control
built into ASP.NET to do what you want.  Read the following article to
figure out which one of the following it is:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaspp/html/aspnet-whenusedatawebcontrols.asp

If you need something more custom, then build a User Control:
http://www.ondotnet.com/pub/a/dotnet/excerpt/progaspdotnet_14/index1.html
Custom Controls are overkill for this project.

As you get more knowlegable building websites with ASP.NET, you'll
naturally gravitate to building your own User Controls to repeat the
appearance and functionality of portions of web pages, similar to
using asp include files or a content manager, but much more powerfully
and easily.  Good luck.